Oh, Diary! Why did I blow my cover?!

But just then, they heard the sound of the garage door opening.

Alan cried out, "Oh shit! Mom must be home!" His erection twitched and he strained to control his muscles so he wouldn't cum. But it was a losing battle, and his cum started to shoot even as he moved towards the pool. He yelled at his sister, "Quick, grab my suit and jump in the pool!"

He staggered to the pool, trying his best to aim his cum into the water so it wouldn't leave a trace.

Katherine and Alan both jumped into the pool and put their suits on after they were already in the water.

Alan figured that was the safest thing to do. The water would remove the smell of sweat and sex.

Luckily for him, he'd managed to fire most of his cum into the pool as he was jumping into it, after which his cock had continued to pump out more semen underwater. He stirred the water to try and disperse his cum. The sexual mood was pretty much broken by the ill-timed interruption.

However, they needn't have worried so much, since it took Susan a number of minutes to carry her bags of groceries into the house and put everything away. She'd had no reason to rush out to the pool, no reason to suspect that anything was going on out there.

Susan took so long to come out that Katherine joked to Alan about starting things up again, right in the pool.

He wasn't amused; he was obviously more concerned about getting caught than she was.

He sought to change the subject, so he asked, "Hey. Where did you get the bikini tan lines? I've never seen you wear a bikini?"

She answered, "You know how Aims and I have been sunbathing together at her place this summer?"

"Yeah?"

"I've been wearing one at Aims' house so I'd look good as a cheerleader, 'cos their uniform has an exposed midriff. Aims is even more daring; sometimes she takes it all off. You know how she is."

"Oh. Does Mom know?"

"She knows about my tanning. She's surprisingly cool with it. I guess she thinks it's a good thing for me to be a cheerleader with Aims. But still, given how uptight she is, I try to stick with the one-piece at our house, especially when she's around."

When Susan finally came out to say hello to them, Alan and Katherine looked as innocent as angels, dressed in their bathing suits and swimming laps in the pool. Alan at least was looking angelic; had Susan looked closely she might have noticed the wild look that was still in Katherine's eyes.

The only close call was that Susan happened to stand only about a foot from a small puddle of Katherine's cum as she talked to them. But she didn't notice, and as another woman was not affected by the pheromones in Katherine's vaginal secretions. Susan commented, "I'm so glad to see you two swimming together. You haven't done that in ages."

With her eyes unconsciously drawn to the puddle of cum, Katherine answered, "Mom, it's this new 'sexing things up' policy. I love it! I'm just relaxing and having so much fun. I feel like I'm opening up all the way and letting in new experiences." She said this last sentence with a special double meaning directed towards Alan. She turned to him and winked, just to make sure he got the picture.

Alan recalled her opening up when she'd spread her gash for him just minutes earlier, and wondered if the "new experience" she was so eager to let in was resting between his legs. He gulped nervously, but his mother didn't notice.

Susan said approvingly, "Oh, that's good to hear. I love how you two get along so well, so much better than most siblings." She smiled benignly. "You're both such perfect little angels!"

Katherine was still randy, so she replied, "We definitely are becoming much closer than most siblings. Much closer! Don't you think, Big Brother?" She giggled happily.

He just coughed nervously.

Susan left a minute later after asking what they wanted for dinner.

As soon as his mother was gone, he burst into anger. "Sis! What the hell came over you? Were you possessed? ARE you possessed?"

In actual fact, Katherine really was more or less still possessed by lust as he asked this. Her entire body was still surging with energy and excitement. But his obvious distress about what had happened cooled her ardor tremendously. As if snapping out of it, she said, "I'm sorry. Really sorry." She hurriedly pulled herself out of the pool. "I don't know what came over me."

As Alan watched her get out of the pool, he felt conflicting emotions. Dang! Sis is sexy! I never really realized how sexy she is before. And she totally wants me. She wants me! Sis! That totally blows my mind. She must be affected by all the craziness going on in this house lately.

But I dunno. If we start doing stuff, everything is going to change. Maybe our close friendship will be ruined if things don't work out.

Hell, what am I thinking?! She's my SISTER! I need to be more... well, disturbed by that! I mean, that's just so fucked up! I came while watching my sister masturbate. Whoa! I can't ever let that happen again. Ever!

Katherine rushed back to her room. Once there, after she'd recovered from her erotic fugue, she burst into tears at the magnitude of what she'd just done. She was terribly worried her brother would hate or reject her, now that her secret incestuous desires had been revealed.

After she calmed down some more, she wrote in her diary:

//

Dear Diary,

I've fucked up in a big, big way! Sure, I had the time of my life, but at what cost? I could have just coasted along, piggybacking on this wild sexual ride that Mom and Aunt Suzy are on. Before long, probably I could have gotten my chances to help Bro do his thing. It would have just seemed like I was a cool, helpful, sexy sister. And then things could have gotten more and more physically intimate from there.

But noooooOOOOooooo! Now, he knows I'm totally in lust with him, and he's gotta at least suspect that I'm in love with him as well. The only way it could have been any worse was if I'd point blank told him, "I love you, and I'm IN love with you. Fuck me now!" And I almost DID say that! Sheesh! Idiot! As it is, he's gonna run in the other direction when he sees me coming. He won't want my help doing his thing, 'cos he'll worry that'll only make things even weirder between us.

Somehow I have to try to undo this. Maybe I can just try to pass my behavior off as some kind of temporary insanity, and not that it's years of secret passion suddenly unleashed. But if I try to play it cool, will he buy my act?

Oh, Diary! Why did I blow my cover?!

//

As she thought about how she might undo the damage, it occurred to her that she could use Amy's love of nudity to mitigate what had happened. If Amy were to innocently help "sex things up for Alan" just by being more "au naturel" around the Plummer house and pool, that might provide some cover for her own over-the-top display to her brother. So she decided to visit with Amy that evening and explain that the changes in behavior and apparel that Amy had noticed at the Plummer house were being done to help Alan "increase his energy levels" by keeping him aroused and interested, and that even Amy's mother, Suzanne, was helping out.