He walked down the hallway, not being completely sneaky, but also not broadcasting his presence. He avoided the creaky spots of the floor, but walked at a moderate pace, his body relaxed. When he reached his sister's bedroom door, he looked around furtively. His parents shouldn't be home for hours yet, but one couldn't be too careful when walking a line. Not seeing anyone, he leaned in and stuck his ear to the door. Soft, scuffling sounds could be heard on the other side. Ben smiled. He knew what she was doing in there, what he had forced her to do. But, it didn't hurt to check, just in case.
He tested the doorknob with three fingers, slowly turning it and bracing the door against the jamb so that it wouldn't make any noise. It was unlocked, to Ben's pleasure, and he was able to gently ease the door open a crack. Just enough so he could peep through and gaze on his sister. Just as he had assumed, she was on her bed. She was spread out on her back, her head thrown back with her legs drawn up before her. The bath towel was gone, her thin bedsheet a poor replacement. The material wrapped around her, molding itself to her shape. He could see the outlines of her boobs, her nipples sticking straight out. The blanket didn't quite reach all the way down to her feet, instead ending somewhere around her waist, allowing him an unobstructed view of her hand pumping itself in and out of her pussy. Unfortunately, her lights were off and the blinds down, so he could not get a better picture than that. The darkness obscured her actual pussy, and he felt an unknown anger rise up in him. He needed to see her. ALL of her.
With the door open, the sounds he had heard before were now unmuted, and he felt his dick stir as he heard her gently moaning. Her feet moved on the bed, and her left hand made soft smacking noises as it went in and out of her pussy. Her other hand was twirling around her nipples, giving each the attention they so obviously wanted.
She moaned softly, turning her head into her pillow to stifle the sound. Her right hand left her tits to grab onto the sheet under her, twisting and pulling just as her body twisted and turned in ecstasy.
"Yes, more, Ben. Give me more!" Bella panted into her pillow. Ben could hardly believe his ears; was she imagining it was him pounding into her, just as he had imagined her?