He cleans himself up

He looked around his room quickly for anything to clean himself but there was nothing. He check his stash of tissues he'd hidden under his bed for his alone time. However, he remembered her used the last of them a few nights ago and had forgot to replace them.

It was then he heard the sound of the bathroom door opening. His sister must have just finished in there. He was glad that she hadn't come out and overheard what he was doing but he wondered what she had been doing in there all that time. Maybe the sight of her naked brother had gotten her a bit more excited than he though it would. He was slightly annoyed he hadn't tried to snoop on her now. If he hadn't just cum, he'd be pretty hard now, imagining his sister fingering herself while thinking about him.

Mark realised he'd need to get to the bathroom to clean himself up. He snatched up his already cum stained boxers and slipped them on. He then moved over to the door and silently opened it. Peeking out he realised that it was clear for the moment. He stepped out into the hall in just his stained boxers with the cum on his stomach still visible.

He had made it halfway and it looked like he was safe. That's when he heard her.

"Hey bro" he heard his sister say from over his shoulder.

"H-hey Ash" he stammered, making sure he was facing away from her so she couldn't see his sticky mess. He did not want his sister teasing him about this.

"You feeling alright?" Ash asked "you've been acting kinda…weird today"

"Wha…yeah, y-yeah I'm fine" Mark replied.

"Mark, why are you just walking around in your boxers?" She asked

"I'm…errrr…just going for a shower" he explained quickly

"Why? It's a bit early isn't it?"

"I dunno, I just feel like having one, okay" he snapped

"Uh-huh" she replied unconvinced "teen boy, walking round his house practically naked, taking showers in the middle of the day. No girlfriend either, yeah, I can guess exactly what you feel like doing now. Maybe that's why you've been acting weird"

"Shut up"

"Enjoy your _"shower" _she said as she disappeared down the stairs and mark slipped into the bathroom. He was lucky he thought. However, he had forgotten about the mirror hanging in the hall and hadn't noticed his sisters grin as she walked away.

Mark slipped off his boxers and hid them at the bottom of the washing basket, before stepping into the shower and washing himself down. He though about everything that had happened today, his new powers and his sister as well.