Be subtle about it. Let it play out slow.

For the most part I'm sticking to the OTHER side of the Story, "Be Direct". I may come back to this side later, but no promises.

"I hope we don't have anything to do today. I feel like doing a whole lot of nothin'" Jane said, now having Jake's attention.

"There's some stuff I wanna do."

"Like what?"

"Hmm?"

"What STUFF do you want to DO?"

"Uhh. Well I think I'd like to play... something. Video game. I will play video game."

"Which one?"

"The one with guns."

Jake dumped what little was left of his cereal in the sink and briskly walked to the living room to play a video game with guns in it. The living room was out of direct view from any other bedroom or the kitchen. So with a little alone time, he booted up the latest Call of Duty and held his controller by his crotch. Every time he fired his weapon, was near an explosion, got a kill, etc. the controller would vibrate on his semi erect dick. That little encounter got him weirdly aroused. He never felt that way about his sister before. It was all so weird, but it somehow felt like it was all ok. Almost like he was created by some horny writer for this very purpose.

Even after a good few games, his dick still wasn't fully hard from the vibration. The vibrating wasn't nearly frequent or strong enough to get very far. Thinking about his sisters breasts, he grabbed his dick on top of his pants and gently moved it front to back while holding the trigger. As his character shot bullets at nothing, the controller vibrated for more prolonged periods. He rather quickly got a nearly full erection. He dick was a bit bigger than average at 18cm, or slightly above 7 inches. It was clearly bulging VERY noticeably on the front of his shorts. After a couple minutes, he was kicked from his game for being AFK.

"Awww. Was I even AFK that long?" He whined out loud to himself

"I'll say. You just stopped and shot at the wall for a few minutes" Jane said, revealing she was watching from the hallway the entire time.

"J-UH-The batteries died I think" He scrambled to blurt out while pushing his cock deeper into his trousers, trying to hide his shame.

Jake stood up, careful to point the front of his pants away from his sisters view as he walked to the TV and grabbed a few batteries from the entertainment stand.

"You just stood there watching? You didn't think to say anything?" Asked Jake

"It was funny." Replied Jane

After switching them out and tossing the dead ones, he sat back down at the couch, crossing his right leg on top of the left to hide his erection. After getting into another game, Jane walked up to him and sat very closely to his right. He was unsure what to say as she sat down by him, touching his arm with her left breast.

"You know..." Jane said in a low sensual tone.

"I think we should hang out more. Get more Brother Sister time..."

Jake shot up

"I gotta go to the bathroom!" He shouted, running to the bathroom nearest to his bedroom.

'Fuck yeah!' Jane thought to herself. 'He's gonna give me some size any minute now!'

After only a couple minutes, Jane felt a warmth at the base of her breasts. Over a period of 10-15 seconds, they slowly grew slightly larger, gently pushing against her bra a little tighter

"EEEEEHH!!!!" She squealed to herself in excitement, massaging her now larger breasts

Jake felt a slight tugging on the skin of his shaft as it grew soft not long after orgasm. He thought nothing of it, and didn't notice such a small change right away.

After another minute or two, Jake walked out of the bathroom and sat back down on the couch to resume playing.

"Have you noticed?" Jane asked

"Noticed what?" Jake responded, turning his head to her. Her breasts where in fact slightly larger, but again he had yet to notice. It was only really apparent to Jane as she knew they were growing.

He looked straight at her boobs, then realized he shouldn't let her catch him staring and looked down. Pretending they weren't the first place his eyes went.

"Yeah idk. Did you do something?"

"Haha! Yeah. I did. But it doesn't matter. Not yet I guess." Jane said before leaving him to himself.

Jake was worried she knew why he went to the bathroom. Of course she did, but he thought it was so unusual that it couldn't be what she wanted. Could it?