MY SISTER'S BET

"Get up from that lazy butt of yours!" screamed my sister from downstairs. I had been alone in the house, playing LoL in my room for hours. When I heard the front door open, I knew Peach had come home. Peach wasn't her real name, obviously, but one given to her by a boyfriend long ago. Soon the name stuck with her friends, and even our older sister Aria used it from time to time. I dared to only once, and stopped when faced with her withering stare. Our parents even used it once in a while, but never understood why we laughed and Peach squirmed. You see, Peach had her nickname because her perfect ass looked like the rounded curves of a firm peach. I always called her Peach in my mind.

Anyway, that's besides the point. I had no idea why Peach would ask me to get off my butt, but I would soon find out. Peach burst into my room without knocking, and I thanked my luck that she hadn't come earlier. In fact, a quick glance under my desk revealed that one of the tissues I had used was still on the floor, probably glued there. In any case, she didn't notice it. "Get up big brother!" she said, a strange expression on her face. I turned around briefly, but kept my focus on the nearly done game. Peach was back from her daily run, and was dressed accordingly: black spandex from ankles to neck. As usual, I could detect a sports bra, but no panties. Damned little tease. She repeated "I said get up!"

"What's your problem?" I asked, irritated.

"Forget about that game, I have a favour to ask you!"

"Asking me a favour by shouting at me, calling me lazy and interrupting my game? Some nerve!" I replied, knowing the game was... and there it was. Another victory.

"You done now?"

"Yes, I am." I turned around fully, resisting the temptation to look at her body. She was damned fine. Both my sisters were, even though they were incredibly different. Peach took after mom; lithe, tall with an all natural, all genetic athletic build. Aria, instead, took after dad, but it worked. It worked damned well. She was smaller than Peach, but with a lot more curves: hips, thighs and breasts that would put most women to shame. I shook my head and tried to focus on Peach. "What do you want?"

"I want you to get in shape!" she said, with that strange expression on her face again. She seemed somewhat angry, determined and tried to cover it with a smile.

"What? What the..."

"I mean it! It's almost midsummer and by September, you have to be in great shape!" she said, adding a winning smile after that.

I paused, looked at her for a bit, unable to figure what she had in mind. "What the fuck is going on?"

To my surprise, Peach took a deep breath and sighed as she let herself fall backwards on my bed. She groaned before explaining herself. "I took a bet. With Jennifer. Oh... that was such a bad idea!"

"A bet? About me?" I asked, dumbfounded. Jennifer was Peach's best friend, another very hot girl with a passion for training. They were both instructors at our local gym. She barely knew I existed, ignoring Peach's gamer brother as if I didn't exist. This bet didn't feel good. At all. "What did you do? What did you bet?"

"Shit!" another sigh. "I bet Jen that I was such a good trainer that could get even you into great shape in four months. Three and a half to be more precise."

"What the fuck would you do that for?" I asked.

"I don't know... I thought I could... But now, seeing you sprawled on your chair in front of your game..."

"You're crazy! Even ignoring your talents as a trainer, why do you think I'd even accept?"

And then my sister giggled. Looking at her as she lay on my bed, I could see her breasts, a large B cup at best, jiggle on her chest. "Well, I told Jen that if I succeeded, she'd have to go out with you on a date."

"The fuck? You think I wanna go on a date with her?" I replied, stunned.

"Hahaha... Yeah right. I know you may not like her or the way she treats you, but I see you looking at her. You'd really say no to a date with her?"

"Well... I do have a decent amount of principles and integrity..." I replied, weakly.

Peach lifted her head from the bed and looked up, genuinely puzzled. "Really?"

"Yeah... I do. But, maybe, not that much!"

Peach laughed, before getting up. "So you'll do it?"

"No way!" Her face fell. It was almost comical.

"What do you mean?"

"I mean that I'd like a date with her, but not if it forces me to starve myself, not play video games, abuse my body and work out hours everyday. She's hot, but there's more to life than a single date with a hot girl, a date that wouldn't amount to anything else afterwards in any case."

"Hmmm. Shit."

Peach jumped back on my bed, on her stomach this time. As she was thinking about my answer, I glanced at that perfect ass of hers. Pretty much identical to Jennifer, in fact. I'd eat that ass. Either of them in fact, sister or not. Damn! I even felt a tingle in my cock, looking at her now. But suddenly it hit me and I asked her : "Er, what happens if you lose?"

Another groan, as she buried her face in my pillow. "I have to record a video of me telling the entire world that she's the greatest trainer in the world, much better than I will ever be, and post it on Facebook. Crap!"

"Nothing worse?" I said, smiling, staring at her ass while she couldn't see me.

"That's utterly bad!" was her quick reply as she turned to look at me. And then, a quick "And stop staring at my ass, pervert!" But her tone was light.

In fact it was an old joke, and I replied with my usual. "If you don't want me staring, don't wear those pants."

I was expecting her to shake her head, but her eyes got bigger as an idea bloomed in her head. "Think about it brother! A date with Jen, with an ass nearly as nice as mine! Think about it, imagine it, picture it in your mind!" She was grinning again.

I couldn't exactly tell her that I didn't need to see Jen's ass given that hers was right there. "Nah... Sorry sis, it's too much work for a meaningless date. Besides, you know I won't get to do more than look."

"Fuck!" she buried her face in the pillow once more. But suddenly she lifted it again and said "What if she—" then stopped, before adding "Staring at my ass again?" Peach laughed. "Come on big brother... you know there are websites with nice asses all over the web." She laughed and tsk'ed me, but not with malice. Peach had always been sweet with me, which has not been the case for Aria. Once she had caught me staring at her generous cleavage and had screamed her outrage. I think Peach took my stolen glances as compliments, which, in fact, they were. That was part of it, at least.

Still on my bed, with her ass still on display despite her comments, Peach's expression changed. I could see it on her face: she'd had an idea. I didn't know if I should be worried. "What I'm about to tell you needs to remain absolutely private. Understood?"

I thought she wanted to spill something about Jen, but in fact it turned out quite different. "Ok sis, I can keep a secret."

"You like to stare at my ass?"

"What? Are you high?"

"Just answer the question, lazy brother!" she was now grinning, and looked like a wolf ready to pounce.

"Er... Sure, of course... You knew that!"

"Yes. So here's the deal. If you agree to train with me for the next three and a half month, I'll let you stare at my ass as long as you want. I'll even wear sexier clothes while we train."

"What? Are you serious? You'd really do that... you'd do that instead of recording that video? Wow, that's quite an ego, sis!" I laughed, but it was to cover my nervousness.

"You bet! So, interested? Think this ass," and she gave it a slap, making its firm flesh bounce, "can motivate you into great shape?"

"You are positively crazy, Peach!" I dared use the name, given the circumstance.

She opened her mouth in surprise, then grinned. "Oh you want that peach right here?" she asked, slapping her ass again. "You want that? Well get off your own ass and put on some gym shorts and a tee-shirt. We're going running."

She then left my room without waiting for an answer. Stunned that it had happened so fast. I cried out "Now?"

"Of course! Let me change and we'll hit the street!" she replied from her own room.

Five minutes later, we were outside in the driveway and Peach simply began running. She had spent the last hour running, but that wouldn't stop her. I followed her, still utterly stunned by what was going on. Then again, I immediately enjoyed my reward. Peach was wearing the same black camisole top with a sports bra, but now had a pair of very short spandex shorts, no panties. Fuck she looked good! I could feel the beginning of an erection as I followed her, and wondered if this wasn't going to cause problems. I was only 19 years old (Peach was 18), and fully aware that erections could happen regardless of the situation.

Soon enough, I fell into a sort of trance as I ran. I was nearly hypnotized by the sight of her cheeks bouncing up and down, twisting sideways slightly with each step. She was essentially naked. I had never seen her run with those shorts before, and they looked like black body paint. They even ran up very tightly in her crack instead of stretching taut between her buttocks. She was essentially naked except for the colour. Despite my arousal, my erection didn't grow fully, and it was just barely uncomfortable.

What soon became uncomfortable was my exhaustion. I really was in bad shape. I said a quick "Peach!" as I stopped, bent over, trying to regain my breath. She came back and stopped really close to me. She turned her back to me, saying, innocently "I'll give you two minutes, then we run back home." I could see her legs very close to me, and eventually realized that I was seeing the back of her thighs. When I turned my head, I found her ass right next to my face. Fuck it looked good! Despite my exhaustion, my cock responded, twitching in my tight shorts. I was maybe 6 inches away, actually too close to see it properly, but I didn't complain. The sin of her thighs was covered with a fine sheet of sweat, making them glow in the sunlight. "Fuck..." I breathed. "Fuck... damn that's a nice ass!" Peach laughed, then slapped my own ass before starting to run again. Shaking my head, I ran after her and tried to find that trance-like state liker earlier.

When we came back home, I went inside to change into my swimsuit and quickly dove in the pool. Peach and I were still alone, and as I relaxed in the pool, I head her voice from the upstairs bathroom window. "Are you sure about this? You really wanna try?"

"Well, why not... I do want to get in shape, and this is probably the best way to get there..."

Two minutes later she walked out of the house with her tiny red bikini. I stopped swimming and came to the edge of the deck, looking up at her. "Peach, you're absolutely gorgeous... I don't know if this type of compliments is part of our deal, but I don't care." I knew I was red-faced and very nervous, but I thought it would be well received. It was.

"Ah... Thanks brother. And, you know, that special permission to stare at my ass can be extended even when we're not training, but only when we're alone..."

With that she placed a towel on the deck, right next to the pool, and lay on her stomach. I spent the next fifteen minutes staring at her entire body as if my life depended on it. When she turned on her side with her ass facing me, which was probably very uncomfortable, I got an extra five minutes to look at her ass with her curves accentuated. "My turn for a question now... Are you sure you don't mind your big brother ogling you like a pervert?"

Peach turned around, on her other side to look at me. "To tell you the truth, I never minded. Sure it's strange, but what's the harm in looking?" As I was grinning, she continued "You know we're not done for today, right? That was just a twenty minute run, in other words a warm-up. In five minutes you're coming out and we'll start working on your abs."

"Aw..." I groaned.

And so five minutes later I was on my back on the grass, trying to get to twenty-five sit-ups. It was relatively fun, though, as Peach was squatting at my feet, holding them down, pushing her smallish breasts in a very advantageous position. They looked bigger, and seemed to grow each time I came back up. After that it was push-ups, with Peach kneeling right in front of me. Every time I was up, I could look at her long, firm thighs. From up close, very close. Then we went through a series of stretching exercises, with me trying to mirror her movements. Slightly out of breath, I said "Looking at you, I'm beginning to understand why you're so popular at the gym..."

"Pfff... Silly boy! I don't go there wearing my bikini for all the perverts!" she replied, winking at me with a smile. "Stretch! Go lower!"

About an hour later she finally said we were done. I knew she had seen my semi-erect cock through my swimsuit a few times, but she didn't seem to mind. She joined me in the pool for a few laps as I simply lay there exhausted. Contrary to my relationship with Aria, Peach and I had always been friendly. Sure she teased my about my gaming and I sometimes let her know what I thought about some of her boyfriends. On the other hand, we never really hung together. Nevertheless, those twenty or so minutes in the pool after training were surprisingly pleasant. Maybe it was because I could be honest with my glances or compliments, but we really connected. When she climbed out, glistening with dripping water and sexy as hell in the sun, she turned and looked at me "Now, remember: your entire body will be really tense tomorrow morning. Don't worry, it's normal. But know this: we will train anyway. If you're nice, I may even massage you before so as to ward off the worse of the pain."

"Don't worry about me, I'll be up for it." I replied, slightly afraid of being sore.

"Yeah... Hopefully not too, ahem... up, for it." was Peach's reply, with another wink.

"Shut up!" I replied, laughing. The little minx was talking about my cock.

She was laughing as well as she went back inside the house. I did my best to stretch in the pool, trying to prevent most of the soreness. In vain. When I woke up the next morning, everything hurt. From my ankles to my neck. I laughed, remembering that I had thought that about my sister's spandex. I groaned when I tried to sit up in bed. It hurt, it hurt bad. I suddenly heard Aria's voice form the corridor "He's up!" followed by Peach's muffled voice from downstairs. Aria came in my room, without knocking.

"Doesn't anybody knock in this house?"

Aria ignored my comment. She was already dressed for work: she spent most of her days at music camp, teaching young kids the rudiments of her art. Despite that type of work, and the clothes that went with it, I could still see the shape of her very large breasts and hips underneath. She said "Peach says that you have to get up now." And then she disappeared. Less than a minute later I heard her leaving the house. I then heard Peach running up the stairs (running!) to stop in my door frame.

"Ready, big brother?" She was leaning against the frame, making her left hip stand out sharply. Peach had nowhere near the generous and feminine hips of her older sister, but in this pose, with her tiny red bikini again, the effect was remarkable.

"Ready to stare at your glorious beauty in the morning light?" I was still sleepy, my head foggy.

"Oh... Thank you sweet brother. I meant ready for your massage?"

"Er, OK." I saw that she had a small vial of oil in her hand. "You're really going to massage me?"

"Sure! Didn't I say so?"

"Wearing that bikini?" I asked, knowing that my boxers would fail miserably at hiding my erection.

"Why not? Want me to go and change?" Peach asked, playfully.

"No! I mean no, no... It's alright."

"I thought so... pervert. getting turned on by his sister... sheesh! That's so bad!" she was laughing, and so was I.

"Well... don't be surprised when you ask me to turn around, OK?"

"What? Really?" she asked.

"Oh come on... You little tease!"

Peach laughed as I turned on my stomach. She climbed on my bed, straddled my thighs with her own and I felt her skin touch mine. When she began working her magic, I was in heaven. I was moaning and groaning, enjoying everything she was doing, from the nape of my neck to the sole of my feet. Softly, she said "There you go big brother... time to turn around." And so I did, keeping my eyes closed. I knew I was rock hard, and that it would be very, very obvious. Peach didn't say a word, but worked all over my chest, thighs and calves anyway. After a few minutes I opened my eyes and caught her looking at my cock. "Who's the pervert now?" I whispered. She recoiled in surprise, and I saw fear briefly appearing on her face. Then she grinned and laughed. "Guilty as charged! Sorry big brother... That wasn't part of the deal."

"Bah... If you're going to wake me every morning with a massage in that bikini, you can do anything you want with me."

"Good! That's good, big brother..." she said, accentuating the word big. We both laughed, dispelling the tension. "In that case, I'm going to ask you to run another twenty minutes again!"

"Aw crap..."

"Get up, change and drink a tall glass of orange juice. Then we'll run!"

Insanely, this became my routine for the next few weeks. When we'd be alone in the house, Peach would wake me up with a bikini-clad massage, we'd run for twenty or twenty five minutes, swim around a bit, she'd then let me see her ass as she sunbathed, cleavage as I did sit-ups, thighs as I did push ups and the most imaginable angles as we stretched and worked out in the back yard. It never became boring. Her naughty plan was working wonderfully well. Even after just three weeks I generally felt better, even if I was sore all the time. And Peach was happy. And we were growing a lot closer. It's as if the special physical intimacy opened the door to other types of intimacy. In these weeks, we've learned a lot more about each other. Even about usually private things. It was a very warm feeling, discovering my sister like this.

After 8 weeks, only 5 left until the arrival of Fall, Peach began worrying. I wasn't going to make it. Jen and her had set specific goals, and while my initial progress had been very good, things had slowed down. Despite all the stimulation, I was getting really tired of working hard and eating a strict diet. And, while I wouldn't say it, staring at her great ass and body every day for hours had lost some of its interest. Not much, grant you, but still... Peach knew we had to change something.

And the solution presented itself because of a special date with her boyfriend. She had talked to me about it for weeks, and when she came out of her room all dressed up for a fancy evening, I was shocked. It's strange how context can affect perception. I've spent the last 2 months with Peach nearly naked for hours everyday. That red bikini didn't hide much. But tonight, seeing her in her new dress all cleaned up, that was quite a shock. Later, I realized that it was her cleavage. Bikinis were nice and all, but I was learning that a nice push-up bra could do miracles. I spent the entire night thinking about her cleavage. I hadn't been a big fan of her make-up, or the way she had arranged her hair: an all natural look fit her a lot more, in my opinion. Yet that push up bra... Fuck! That night, and not for the first time, I masturbated myself to sleep thinking about my sister.

The following morning, there was no massage in bed. Peach had returned from her evening very, very late. I woke up first, broke my fast with the rest of the family and Peach was still sleeping when everybody left. I crashed in front of the TV, glad of a break this morning. Around 11, I heard Peach waking up, going to the bathroom and heading back to her room. I grinned and went up, carrying her bottle of oil. When I cracked the door to her room, I whispered her name. I smiled as I heard her croak a gravelly "Yeah?"

"Ready for our 45 minute run?"

"Forget it..." she managed to reply. "My head is still spinning!" she cried.

"Ooh. Did you drink water in the bathroom, just then?"

"Nope."

A minute later, I was back in her room with a huge glass of water for her. "You're dehydrated... You should know better, miss trainer."

"Pfff..." she said, reaching for the glass.

It was still very dark in her room, but I saw the silhouette of her right breast as she reached for the glass. I pushed my luck "Feel like getting a massage?"

"Oh gods yes! Would you?"

"Of course... You've given me one nearly each morning, all summer long."

"Oh, wait... I'm naked." she said, smiling a lazy smile. "Throw me my underwear."

Looking around, I found her magical green bra and panties, and couldn't help but steal a long look at the bra. "There you go." I said.

"Ha! You liked that bra from yesterday, didn't you?" she asked, grinning.

"Er, well..." I mumbled.

"Cut it out! I saw your eyes bulge last night! Crazy, no? Given that you've been staring at my breasts in a bikini everyday..."

"Well, not quite the same effect."

"I know... But it won't work for a massage. Take the blue one in the second drawer."

It wasn't a super sexy bra, but it wasn't a huge sports bra either. "There you go again."

"You have the oil?" she asked while putting her underwear under the blankets.

I spent the next half hour massaging, caressing, enjoying and revelling in my sister's tight body. Gradually she came back to her usual self and soon we were chatting. When she turned on her back and I did her front, she glanced at my hard cock through my boxers. "Even after two months? Thanks, bro!" she grinned.

"Thank you, Peach. Three months ago, could you have imagined that I would give you a full body massage in your bed, wearing nothing but flimsy underwear?"

"Nope, never. I'll have to thank Jen for that!" she laughed.

"Thank her for me as well! I got the better of this deal, sis! I think I'm going to miss these mornings and special staring permissions once Fall gets here."

She looked at me, from between her breasts, with a soft smile as I massaged her thighs. "Me to, big brother." After a brief pause, she said "Think you could do 35 sit ups this morning?"

"Aw... No way. I'm sorry if I'm not getting better fast enough. I'm going to die before getting to 35."

"Shit... All that hard work..." And then, just like what happened at the very beginning of this crazy bet, her face changed, and I knew she'd had an idea. "Hmmm, just how much do you like my green bra?"

"Er, quite a lot, why?"

"Give me thirty minutes, and meet me in the backyard, already warmed-up. Think you can jog alone today?"

"Maybe, yes, just today..." I replied, a half-smile on my face. Fixing her ass while I jogged had become a wonderful combo.

"Ok, see you then!"

When I ran into our backyard, a bit sweaty but not drenched like I was at first, I stopped dead in my tracks. Peach was standing in the yard, with her green lingerie. And while, in absolute fact, her red bikini exposed more skin, I was nonetheless shocked. Shocked at just how sexier she looked. Fuck! I felt a buzz in my lower belly and had to refrain from growling out loud. My body, flushed with hormones from the run, knew what it wanted. "Come here and do 35 sit-ups. Right here and now. I know you can do them." And so I came. So to speak, at least. I was used to those sexy sit-ups, bringing my face near to her bikini cleavage. And so I sped through the first twenty sit-ups as usual: Peach was squatting and holding my feet down. But this morning, I made it to 27 a lot easier, staring into that wonderful cleavage.

When I began to groan with each repetition, Peach repositioned herself. She moved in much closer, sitting herself on my feet and holding my thighs with her hands. And she leaned in. When I came up for my 28th, I was really, really close to her breasts. I had become used to being maybe ten inches away, but now it was three. Very fucking close. 29, 30, 31, all the same. I had never broken 30 before, and had four to go. As I went back down, I said "What if I can..." then paused as I got up, then added "touch them?" as I rose for my 32nd.

"I'm not gonna move until you reach 35."

I rose for my 33rd and reached as much forward as I could. Maybe one inch away. As I fell, tuckered out but convinced I could reach them, I took a quick deep breath and pulled up again. And so, for the first time, I kissed the inner swell of my sister's left breast. Down, then back up again, and I licked her right breast from the exposed base until it flared out on her chest. When I crashed down after that, Peach said "Keep going brother... If you can reach them again, I'll hold your head there for a few seconds." My eyes bulged wide opened and I tried again. I was experiencing more pain than ever before, but I knew I had to do it. And so I did. And Peach kept her promise. For those few very quick seconds, I had my face buried in her cleavage.

Peach didn't have very large breasts, but she was wearing a bra that made them seem much larger, was bent forward, arms in front to hold me, and, most of all, she was my sister. I had my face buried between her breasts, kissing and licking as much skin as I could find, even darting my tongue under that magnificent bra. Instead of letting me fall back down afterwards, she gently guided me, following me most of the way. She ended up nearly on all fours above me in her sexy lingerie, my hard cock obvious and my saliva all over her cleavage. "There you go..." she whispered as I trembled, for many different reasons. "I knew you had it in you, brother!" I was in so much pain, and my brain was still overwhelmed. I only managed a little smile.

A bit later, when I managed to get up, she had dried her cleavage with a towel and was walking back towards me, grinning. Still worried, I asked "Are you sure about this Peach?"

"About what?" she asked, apparently genuinely puzzled.

"Well, I mean... about... my face in..."

And then my sister, my sweet sister who had allowed me to kiss her breasts, began laughing. "You worry too much, bro. Are you enjoying this... whatever this is?"

"Of course!" I briefly looked at my shorts, where my erection was plainly visible.

"Do you believe you're forcing me into this?"

"Well, no, but—".

She interrupted me "Know one thing, brother. I'm not going to do anything I might truly regret for that bet. And the same goes for you." she said, leaning in close to my ear to whisper "The moment you don't want to kiss my breasts, just let me know and I'll stop you."

We laughed again and spent the rest of our two hours together having a lot of fun despite the pain. The lingerie helped. A lot in fact. It's strange how human motivation can work, sometimes. We made sure to be decent before anyone would come back home, and I spent the evening relaxing, preparing for tomorrow. In my bed, as I was getting ready to finally masturbate to images of my mouth on Peach's breasts, she opened the door. On all fours on my bed, she leaned in and whispered "Tomorrow morning, you're going to do the full hour jogging with me. I'll give you something to look at... Believe me you'll want to follow me."

And so I did. I did get my morning massage, with her red bikini again. But I did get the feeling that I was feeling more of her body. Usually she moved from top to bottom, but this morning, after having done my legs, she moved back up, sliding her own inner thighs around mine. When she worked on my back again, I could feel her skin gliding on mine. And while I was on my back, the feelings were even more intense. Once, when she reached down to get the bottle, one of her breasts grazed my belly. It had never happened before. An accident, perhaps? Before finishing, she leaned forward and used her entire forearms to massage my chest, forcing her breasts much closer to my skin.

After my shower, I met with her outside, and was really pleased to see that she was wearing a skirt. A very short skirt. "Ready to watch me run and bounce around with this?"

I grinned, shaking my head. "You little tease!"

"I'm only a tease if you don't get to see anything... What if I told you that I'm only wearing a g-string under it?"

I couldn't reply, and motioned her to run. We did our one hour. One full hour of jogging. It was mindbogglingly pleasant. When we ran through the part of the trail in the forest, I noticed that Peach began to jump and bounce around a lot more. So did her skirt. I could see most of her ass as she did, a lot more than her bikini revealed. There was a steep cliff near the end of the forested path, and usually it was hellishly difficult for me. But now, I was looking forward to it. Looking up her skirt as she ran all the way up, I was panting and grinning. Peach suddenly stopped, and said she had a small cramp in her thigh. She then proceeded to bend forward, stretching herself. And, obviously, showing me her ass completely. I stared at her, fascinated by the sight. She laughed as she resumed running, daring me to catch her.

That entire week was mesmerizing. Lingerie, skirts and g-strings fought with each other in my mind, and the breast-kissing sit-ups became the norm. Once, as she was holding me for the final gift, I felt my tongue reaching her nipple under her bra, feeling its taut, hard and excited flesh. I was briefly afraid that it would piss her off, but she simply smiled as she gently lay me down afterwards.

The next week was even more intense. Both more gruelling and wonderful. The early massages had once again become more than just fun: I truly needed them after what Peach put me through. But everything was becoming even sexier. It was otherworldly. At one point, she removed her g-string from under her skirt as we entered the forest for our jog. And then she sped up like the damned road-runner. But I caught up quick, amazed at the naked glances I was now allowed. When she reached the top of the cliff, she slowed down, allowing me even more. I saw her pussy flashing, confirming that she was mostly shaven.

When she paused at the edge of the forest, I expected her to put her g-string back on. Instead, she handed it to me and said "If you can get back home before me, I won't wear them for our entire jog tomorrow." And then she sprinted. But that was a miscalculation on her part. Speed had never been an issue for me. I was significantly taller than she was, and had always been a good sprinter. Long legs will give you that. And in the past few months she had given me a lot more endurance. We had about a ten minute run in front of us, at most. I passed by her after three minutes, and despite her best efforts, she couldn't catch up to me. And the next morning's jog was indeed panty-less. Which was amazing. After that morning jog, I had a very good idea of what her pussy looked like. Even more amazing, that panty-less run became the norm.

It was just crazy. Then, as the deadline drew nearer yet, Peach stepped up the craziness even more. Before we began our sit-ups, she said that if I hit 40, she'd remove her bra. And as magnificent as that bra was, I really wanted it off. By 32 I was kissing her breasts, not even slowing down. When I hit 39, groaning all the way, I didn't even bother trying to kiss her breasts, but forged on to 40. Peach was laughing as I crashed down after my 40th sit-up, and unclasped her bra. She placed her hands on her hips, grinning and red faced as I stared at her breasts. They were as stunning as I thought. They were not overly large, but they were still round and full, thrusting forward proudly. Laughing, she made them bounce left and right a few times as I stared at the pale pink aureolas and nipples. What Peach hadn't counted on was the fact that I had enough energy left for one last sit-up. She cried out as I sat up again and closed my lips around her left nipple. In reflex she placed her hands on my head, pulling me close. A few seconds later, she felt me shake and tremble and she guided me back down.

"Damn!" I said, pain threatening to overwhelm me, as much as pleasure.

"You sly devil!" Peach said, grinning and even redder. "Do you realize that you've now officially gone further than Matthew?

"What? Get out of here!" As crazy as things had been, it had not prepared me for the following conversation.

"I'm serious." She took a deep breath, but didn't reach for her bra. "In fact, we both want to go slow. I went too fast with Jordan, and I really don't want to make that mistake again."

"Oh..." I didn't know what to say or do. "I'm sorry?"

Peach turned to me and smiled. "Thank you, even if you're fumbling for the right words." with that, she lay down on the grass next to me, on her back, still braless. "Can you keep a secret?" she asked me.

"Peach, do you really need me to answer that? Do you realize that if any of what we're doing were to come out, we'd be in fucking deep trouble?"

I was really glad to hear her laugh out loud. "You're right. So, here goes: I'm not even sure I'm technically a virgin anymore."

I wasn't expecting that. It took me a while to react. "I, er, didn't think you were, actually..."

"Really?" she seemed genuinely surprised.

"You've had quite a few boyfriends already, and are, blindingly obviously, very at easy with your body. And in any case, how can you not be sure?"

"Remember Kevin?"

"The bastard? Yeah I remember."

"Well, we were fooling around, naked in his bed. I made him promise that we could do anything except penetration. And it was really, really fun. Until he tried to penetrate me. And he did, at least part of the way."

"Fucker... He doesn't know what's coming his way the next time—"

"Shhhh brother. Let it go. I've made my peace about that. But did he penetrate me deep enough?"

The entire conversation was utterly strange. Peach and I had gotten very, very close in the last few months, spending inordinate amounts of time together, working and talking. The strange physical intimacy, usually not shared between brother and sister, had definitely allowed our relationship to deepen. Judging by her actions with me and her confidence, I knew she was perfectly at ease with her body and with sexuality, despite her young age. She seemed a lot more confident than I was, in any case.

"Penetrate you deep enough? To count as losing your virginity?"

"Yeah..."

"Nah... No he didn't. I think you'd know, and in any case you're going to lose it when you decide to. Look, " I said, taking a pause. "I've had sex maybe five times with my current girlfriend, so I'm not an expert. But I'm pretty sure you get to decide."

"Bah, it's not that big of a deal... It's not as if we were still saving ourselves for years until our wedding night. I've found that I get bored when my friends talk about the big night. But you're right, I think I'm going to give it to whoever I want, regardless of what Kevin did."

"Good for you!" I said, turning on my side, and marvelling at the fact that she was still topless.

"I'm a virgin then!" she added laughing.

"Yeah... The most confident and sexually awake virgin I've ever seen!"

"Thanks big brother!" she said, before kissing me on the lips. Really quick, almost innocent. Then, without leaving me time to react, she got up and said "Now, we have to find a way to make you work on your push-ups. Hmmm, still wanna stare at my ass? Are you bored yet?"

I grinned, shaking my head. "Nope!"

"OK then, you're going to get your best look yet! Do 30!"

As I was labouring through the first 20 pushups, I wondered what she had in mind. As I called 25, she dropped on all four right in front of me, her panty-clad ass way up in the air. In that position,I could only look at it when I was fully up. But boy could I look! Soon I realized that she wasn't really offering me her ass. Instead, it was her pussy that was in obvious display. She had her own legs below me and between my arms, so when I pushed up I was just about touching her. At this distance, the lace of her panties became see-through, and I got quite the view. Soon I was going for 30, before crashing to the ground.

"See what happens when you're properly motivated?" she laughed.

The toplessness became part of our daily routine, but usually we stayed indoors for that. The pussy tease as well. Three days later, as I was pushing up for my 26th push-up, I called her a tease. Her answer was simple "Do 30 and I won't tease anymore." I felt a rush of pleasure in my belly, and renewed strength. When I did reach 30, her hand appeared and pushed the crotch of her panties aside. I had gotten very good looks at her pussy every time we ran up the forested path, but this was something else. I was shaking as if an earthquake had its epicentre in my chest, but I remained there as long as I could. Five seconds. But five glorious seconds. Sprawled on the grass, trying to control my pain, I croaked "Damn it Peach... You're fucking gorgeous from very damn angle!"

"Wow... Gracious even when exhausted! Wait and see what I have in store for our jog tomorrow... Fifty minutes."

"Only fifty?"

"Yep. The same route though, so we'll have to go quicker."

"Crap..."

As I went to bed that night, having seen my sweet sister naked from every angle, having sucked on her breasts more than once, I was rock hard. That too was now part of my routine. I masturbated while thinking about her, cumming inordinately fast without the need for porn. When I saw myself in the mirror behind my door, I was shocked. Mom and Dad had made some comments, but I thought they were just encouraging me. But after ten weeks or so, the results were clearly visible. I had lost a lot of flab and gained muscle mass, and I knew that my cardio was above and beyond what I had before. I cleaned myself as good as I could and went to bed. As I reached for my boxers, I paused, and decided to let them there. It was only fair that Peach would see me naked. I almost masturbated again before going to sleep, but resisted the urge.

When she opened the door the next morning, her red bikini telling me that we were alone, I turned on my stomach. When she pulled the sheet and gasped, I turned my head around and looked at her. She was grinning and said "About time!" and we were laughing together. I had never been so at ease and comfortable with another girl in bed. The fact that she was my sister made things a bit stranger, but somehow a lot naughtier. The back massage went pretty much as usual, but when I turned around, Peach kneeled above my thighs and stared at my cock. "Hmmm, very nice big brother. Very nice. Gisele is a lucky girl..."

"Well, that may be, but she doesn't seem to want to have sex all that often."

"Yes, you told me... four times only, and eight months together now?" she asked.

"Yeah."

The utter abnormality of the situation didn't even register, for either of us. We were brother and sister, talking about our sex life, while she was massaging me, wearing nothing but a tiny bikini, and I was naked, my erection proudly displayed. The only time I felt her hesitating was when she did my shoulders, forcing her to bend further forward, making her belly touch my cock. But even then, she fumbled with a single word and kept going. Before finishing, she sat up straight and looked at my erect cock. "I'm no expert, but that's a really nice cock... Shame on Gisele if she doesn't want to enjoy it more often..." she sighed. "Meet me downstairs in ten minutes!" As I showered quickly, her last comment struck me. That was rather intense, despite everything.

As we ran, her with the same skirt and no panties, I tried to discover what she had in mind. When we came to the forest, she stopped, and asked me if I was ready to run really fast. Of course I was. In seconds, Peach had stripped completely and said "If you can catch me, we'll do your exercises naked at home!" And she bolted. Like a young colt. After just a few steps, she threw her few clothes (camisole, skirt and bra) up in the air. "Bring my clothes!" she cried as she disappeared around the first bend. Shit! I was faster than she was in a straight line, but this was no straight line! I grabbed her clothes as fast as I could and exploded after her.

It was profoundly strange, to chase after your own naked sister in a public path. Granted, we hadn't seen anyone here since I began running, but still, the probabilities were not zero! As I ran, I caught glimpses of her trough the trees, and sometimes had a great view of her athletic body running in front of me. The cliff at the end of the path was coming really soon, and I wasn't sure I would be able to catch her. But the thought of doing our exercises naked together was enough to send an added shot of adrenaline and testosterone through my system and before we reached the top of the cliff, I caught her. And I mean caught her. I grabbed her arm and as we stumbled to a stop, managing to remain standing, I was holding her in my arms, naked or not. We were both breathing like steam engines, but we clung to each other nonetheless.

Eventually we let go, gently, smiling at each other. She put her clothes back on and said that we still had to make the 50 minute time. We did, easily. The sprint made all the difference. Back home, after jumping in the pool to clean ourselves quickly, we went down to the basement for privacy. We then stripped down completely and, as if nothing was out of the ordinary, we did our usual routine. Well, let me tell you that doing sit-ups is by far the worse way to show off your cock. Damn! I was hard as a rock and my cock looked like it was three inches long as I sat up. Luckily it didn't look as bad when I was down, but still! Nevertheless, I was still able to kiss and suck on her breasts, feeling her fingers tighten in my hair as I finished.

When I did my pushups, it was remarkable how many I managed to do. I was staring at my sister's naked pussy mere inches away from my eyes. And lips. I really, really longed to reach out and kiss it, lick it and eat it. But every time Peach and I went further in this strange intimacy, it has been her making the decision. I would leave it to her again. During the stretching exercises, I got to see everything I could have wished for, from every angle.

As usual, the naked addition became a routine. The next week, the second to last before the deadline, Peach added two new exercises. Painfully hard. They were endurance exercises, designed to tone my core. The first one was the table, where I ended up transforming myself in a table, with my knees bent at 90 degrees and my arms under me. I was facing the ceiling, and had to hold the pose for as long as I could. After that, I had to do the plank, which was essentially the reverse, holding myself on my toes and elbows, facing the ground.

I was horrible. But Peach was confident that in two short weeks I would get a lot better. And I did, thanks to her, ahem, encouragements. After the third day, Peach decided to stand over me as I did the table. Yep, her legs on either side of my hips, her opened pussy above my cock. She timed me first, then added this "If you last for more than one minute, I'll slowly lower myself towards you. I'll stop if our bodies touch or if you fail." If our bodies touched. Understatement of the year. If her pussy touched my erect cock, was more like it. And for three days I failed. Utterly. Then, on the fourth day, I spent the entire morning focused on that exercise and decided that I was going to maintain the position no matter the pain. And it worked. For three seconds. But when I felt her pussy, quite wet actually, touch the underside of my cock, I felt electrified. When I fell down after those seconds, Peach simply jumped up and clapped, congratulating me. I wasn't sure that she fully realized that she was congratulating me for touching her pussy with my hard cock.

The same thing finally happened, during the last week of exercises, with the plank. I couldn't hold it long enough. Ironically, I learned that I could hold my erection for a very long time, but the plank... After the fourth day, Peach said pretty much the same thing "If you hold it for more than 1 minute, I'll come and place my pussy just under your head. If you hold for two minutes, you can do whatever you want... as long as I remain in the position. As soon as you fall, I pull away."

"OK, I'll give it a try." I said, as if it was nothing out of the ordinary.

This time it worked a lot faster. The second day I reached the 1 minute mark and watched my sister sit in front of me before opening her legs and scooting right under my face. It was amazing, amazingly wrong and amazingly wonderful at the same time. And while I failed to reach the two minute mark during the first two days, I came close. I finally succeeded on the third day and finally heard her whisper "Go ahead..." and so I did, licking, kissing and eating her pussy, devouring her as fast as I could for as long as I could. She did pull away when I fell, but only just out of my reach. She was smiling as I turned to look at her.

Two days later (two days during which my cock and mouth touched her pussy), which was also three days before the end of summer, we decided that the last 2 days would be for rest. It wouldn't help if I arrived at the test and was exhausted. So, as Peach entered my room completely naked to give me my massage (not the last, she had sworn) with her bottle of oil and her cellphone, I asked "Think I will make it sis?"

"Yeah, pretty sure you will, big brother. Here, have a look at what you looked like 3 months ago."

"Oh my gods!" I swore.

"Yeah. You will make it. Now lay down and relax. And enjoy."

When she was done with my back, Peach asked me to turn around. When she climbed over me again, she lowered herself a bit higher than usual, placing her pussy against the underside of my cock. By reflex, both my hands went to her hips before I pulled them away. As she massaged my chest, she began moving on my cock, sliding up and down. Then grinding herself upon it. It was completely surreal. I didn't say a word, and she didn't go any further, but it was killing me. When she was done, though, she said "No jogging this morning. I need you to nail the table and I have the best idea to motivate you."

I had no idea what she had in mind beyond what we were already doing. But as I assumed the position, she squatted above me. Soon she was letting her pussy slide on my cock, form my balls to the tip. Then, looking at the watch, she moved back above my balls and grabbed my cock with her hand. Pulling it up, letting a thick glob of saliva to drop on it, she coated my entire length. "Don't even think about moving, and keep your mouth shut." she said, a curiously serious expression on her face. "I've been dreaming about this for weeks now..." And with that, she lifted herself up, pulled on my cock and empaled herself upon it. "I choose you, my dear brother."

I was floored. And I didn't care about the table right now. Not at all. My cock was inside my younger sister's pussy, sheathed as deep as it would go. I lowered myself to the floor and grabbed her hips again, pushing up so that the last inch drove me to her depth. I had been refraining from initiating more contact, and Peach had wanted nothing else... Fuck! But this was so damned good! Peach rose up upon my cock and lowered herself again. Even better this time! It was mesmerizing. Soon her saliva and her own juices were flowing all around me and we were fucking properly. I couldn't really believe what was happening, after having imagined it so many times!

Peach placed her two hands on my chest and increased her rhythm. "Damn, brother... This is so fucking good!" It was, and then some. She was technically a virgin (well, had been!), and I was barely experienced, but we both cared so much about the other that we were attentive to the smallest of sounds or movements. I was fucking my sister! It was not possible, yet there I was, thrusting into her wet, burning hot pussy as she moaned above me, as thrilled as I was about the whole thing.

When I saw her breasts bounce back up after Peach drove herself down harder, I moaned and opened my mouth. So firm, so perky, so beautiful. I reached up and despite having kissed them and sucked on their nipples, I had never touched them with my hands. As my fingers closed around their flesh, I closed my eyes and tried to focus my attention. But Peach's pussy was overwhelming me. It felt as if I could feel distinct sensations all over my length with each of her strokes. Everything was new, everything was bright and glorious.

Eventually she sped up even more and things got even better. She was now riding me quite fast, driving herself upon me with each downward stroke. I could feel her squashing her clit on my pelvis, and could hear her moans getting higher and higher. Soon I saw her climaxing, her mouth opened and head thrown back. And then she screamed. Loud! She grabbed my skin and muscles in her hand and squeezed hard as her first penetrative orgasm rocked her. Orgasms, I should say. When I grabbed her ass very firmly and pulled her harder against me, it triggered a second, very fast climax. But she never stopped pounding me into the floor, moaning my name and screaming her peaks of pleasure all the while. "Oh my fucking Gods..." I groaned, letting my sister know that I was about to climax myself.

"Oh, oh, oh! Cum inside me! I want your cum to be the first... Fill me! Fill my little pussy, big brother!"

Did I ever! I had taken the habit of masturbating every night, but I emptied my balls of everything they had that morning. Soon I heard the wet, sticky sound of my my cum being pushed out of her tight hole with her thrusts. And, like her, I never stopped. I kept fucking her, thrusting myself up inside her, willing my cock to remain hard. And it did. But Peach came again. We would soon learn, in the months to come, that it was really easy for her to trigger multiple orgasms. It had happened a few times while masturbating, but when she fucked, it was almost every time. I didn't know that at that moment, and I felt like a fucking God. Here she was, laying flat above me, squeezing me hard as she came again a third time as I held on to her ass.

After pushing one of her leg lower, I rolled her onto her back and mounted her in the missionary position. Hard. By now we were both barely coherent, and Peach was writhing below me, driven hard by my pelvis against her clit and my cock deep inside her. "Fuck you have a big cock brother!" I knew I didn't, not objectively at least, but hearing those words had a striking effect on me. I was already hyper confident with her multiple orgasms, and now I felt even better. I felt, with every stroke, like a huge piston giving my sister immense amounts of pleasure.

Nevertheless, I eventually pulled out and turned her on her stomach. "Place your hands on your pussy." I asked her. When she did, I kneeled above her ass, slapped it a few times with my cock and found her pussy again. I then slid both my hands under her body, and hooked my hands on her shoulders. Pulling myself up, I began fucking her harder than ever before. Not too fast, just really hard. Peach, in great shape, took it all in stride and I heard her moans become staccatoed, chaotic. So did her breathing. I could feel her round and firm ass on my skin, clenching and releasing in time with me.

Eventually she began spasming in off-beat rhythm with me. Her breathing became even more ragged, and her moans crescendoed again. I was stunned that she was going for her fourth orgasm in less than twenty minutes. We were both covered in sweat, our skin sliding against the other's, our sexes in perfect sync. I felt Peach's entire body clenching around her clit as she was rocked, and raked, by her pleasure again. From her mouth, a mess of screams, groans, growls and moans were flooding, filling the entire house with her overflowing pleasure. My own pleasure followed suit, driven by the clenching motions of her pussy around my cock, her powerful muscles overwhelming my cock.

Sprawled over her as our bodies finally had their fill, I slowly fell to the side. Peach turned to her side to face me, a bright smile on her face. "Oh my Gods! What the fuck was that? This is insane!" she said, laughing and grabbing my chest once again. Reaching down between her legs, she pulled her hand back and looked at a glob of my sperm. "So, I have my big brother's cum all over me... Finally! Fucking finally! Took you long enough!" I stared at her, astonished by the intensity of her lust. When she licked her finger clean, I grinned, knowing that soon, very soon, my sweet sister was going to be the first girl to suck my cock. I pulled her to me and held her tight, and she hugged me back, really hard. We kissed, kissed for a long time, naked in our basement, surrounded by discarded training equipment. We were at peace despite having committed one of the worse sins and worse illegal act possible.

At peace, and alone. At least, that's what we thought. But we wouldn't learn about that until much later. In the meantime, I passed Jen's damned test and smiled as she cursed, acknowledging that she would have to be forced to have a date with me. But as sad as she was to spend an evening with me, she became positively furious when I said that I really didn't want to. In fact, two of her friends had to restrain her because she wanted to hit me when I refused her. In fact, even when one of those two friends winked at me with a smile, I knew I didn't want any of them. I couldn't date my sister, obviously. Heck, she even had a boyfriend! But right now all I wanted was to be with my sweet sister Peach, alone in our basement, our rooms, our beds, in the kitchen, in the pool, etc...