Of course, her 'acting' isn't able to trick Jay at all, as soon as she appears at the stairs, he knows something's wrong, but he decided to play along.
"Let's go! By the way, since my bicycle is still a little too high for you, I bought you a smaller one, it's in the garage. It's also your birthday present, happy birthday Jee Eun ah!"
"...thanks oppa." She thanks him with a forced smile, seems like she doesn't like the present at all.
As the garden is pretty spacious, He will be teaching her there, so that she won't injure herself badly if she falls.
After she readies herself on the bicycle, he proceeds to teach her all the basics she needs to know. Surprisingly, she finds the balance pretty quickly, it only takes around 30 minutes for her to get a hang of it, she can even cycle in a straight line without Jay supporting.
Slowly but surely, her mood slightly got better, smile begins to appear on her face. At the end of the lesson, she is able to make turns with ease, so Jay decides to let her cycle outside the garden, and he follows tightly behind her, with his own bicycle.
They cycle around the area until Jee Eun gets tired, then they cycle home together.
When they get back to the house, the whole place looks deserted. Jee Eun calls out to her grandma and brother but doesn't receive any reply, so she goes to check every corner of the house.
When she goes upstairs, Jay quickly makes a phone call to Yunho to signal them to get in the house and get ready for the birthday surprise for the little princess.
When she is finally back downstair, everyone including her parents is waiting for her. Jay comes out from the kitchen holding a birthday cake and starts to sing the birthday song for her, everyone joins in, that's when she finally realizes and remembers today is her birthday.
Not knowing what to do, she waits for them to finish the song, and slowly walks in front of Jay and slaps his arm.
"Oppa! You planned this didn't you."
"Yeah! You like it?"
"I like it, but I would've preferred you to tell me everything and not keep a secret from me, because this is kinda embarrassing."
Her face gets redder and redder, because she is just shy.
"It wouldn't be a surprise if I tell you about it, now make your wishes and blow the candles, everyone is waiting to eat the cake."
"Nae oppa~" She closes her eyes, clasps her hands and makes her wishes, nobody knows what she is thinking, then she blows the candle.
"Happy birthday Jee Eunnie~ You get to eat the first slice of the cake, the rest is ours."
"Mwo? Only one slice?! I want more!"
"You can have more when Eun Jee is here, she baked a cake for you herself, you can have that one to your own."
"Huh? Eun Jee is coming too?"
*door bell
"That's her."
"I will go open the door for her!"
She rushes to the door excitedly, as expected, Eun Jee is standing outside with her family while holding a cake. Then the two girls hug each happily and start jumping around like rabbits.
"Jee Eun ah, don't forget your slice here! Everyone's waiting."
"Nae oppa!"
...
Jee Eun's parents and grandma gathered at the living room and chatted with Eun Jee's parents.
Jay and the boys sneaked into the storage room and drank some soju, of course it was Yunho's idea, he found boxes of them when he was wondering around the house the last time they stayed here. When they got out of the room, everyone was drunk except Jay, it was like the alcohol had no effect on him. They also got lectured by Jee Eun's grandma when they got exposed because of their smell and red faces.
Jee Eun and Eun Jee played with each other the whole evening in Jay's bedroom, you can sometimes hear them giggling through the door.
Oh right, and Jong Hoon, well he slept through the whole thing, seems like his sister birthday didn't mean anything to him.
They partied the whole day and only went home when it's night time, Jee Eun's parents left too because they already postponed their work for too long. Now, it's just Jee Eun and Jay in their bedroom.
"Oppa... thank you for the birthday party, it's the best birthday of my life, I'm very happy."
"Yah! This is what an oppa is supposed to do, and we will have more to come in the future, next year, next next year, and the years after. This isn't for free though, I expect you do the same for me too."
"Too bad yours had already passed, you will have to wait for it next year, hehe."
"Hmm... I can wait. Oh, almost forgot, I got something for you, this is your real birthday present."
"Really? I thought the bicycle was it."
"Nah, that was just to tease you, hah, you were so disappointed when you saw the bicycle."
"Err... I do like it, you just picked the wrong time to give it to me."
"I know I know... ah, found it. Here you go!"
"What is this? A piece of paper?"
"That piece of paper can earn you lots of money in the future. Turn it around and look carefully."
"...these are lyrics!"
"Yeap!"
"You wrote this for me?"
"Yeap! You can use this as your first song when you become a singer in the future."
"Really? I love you so much!"
"Not so fast, read the lyrics first, and see if it suits you, and be honest."
"Nae oppa!"
After 5 mins of reading...
"Oppa, this isn't a solo song is it?"
"Good catch."
"It doesn't feel like a duet either..."
"Mmhmm."
"What is it then?"
"You will know it in the future."
"Huh?! If you don't wanna tell me, why give it to me right now?!"
"Just wait like 7 or 8 years."
"Argh! I hate you!"
...
Next morning
Jay wakes up earlier than usual to pack his stuff quietly, then he freshen himself up in the bathroom.
He covers Jee Eun properly with her blanket and leaves a note for her on her table. Then without waking anyone up, he leaves the house secretly.
The note:
'Jee Eun ah, my trainee life begins today, please cheer me on, I will wait for the day when you stand by my side on stage, performing together, hwaiting! Saranghaeyo~ <3
...