Karen takes a shower

"I think I'd better take a shower."

Ignoring the fact that he'd just covered her with sunscreen, Karen hopped out of the lounge chair and headed for the shower.

Matt waited a couple of minutes, until he not only heard the shower running but actually heard Karen step into it, then pressed his ear to the bathroom door.

He wasn't sure what he was listening for until he heard it. Something he was highly familiar with from all of the female masturbation chat sites he frequented, but that he'd never actually heard before in real life... the sound of a woman getting herself off.

Clearly Karen was trying to keep the sound down. Equally clearly, she wasn't being completely successful.

Matt thought about what a jerk he was being for evesdropping on his sister. A good guy would walk away, turn on the TV, and tune out all thoughts of his naked sister standing in the shower... maybe with her hand up her pussy, maybe with the hand-held shower spraying directly into her. Maybe with one of her small but nicely shaped tits in one hand while she fingered herself with the other.

Matt wasn't that nice guy.