She sits on his cock

Melanie rolled back over and shoves her whole body backwards, smashing his hard cock into her ass crack. She wiggles as he hotdogs her ass, then leans her whole body back against his and looks up at him, eyes sparkling. He looks down at her, hardly able to believe that he is here with her. Soapy water runs down her small, mostly flast chest, over her big and hard nipples.

"Happy birthday, big brother" she said, then ground her ass into his cock, making him moan.

Without warning she slides her ass up his shaft and out of the water. For just a second he is face to face with her asshole and pussy. She is absolutely beautiful from that angle. Then he feels a hand gripping his cock, and she slams her body back down into the water, landing perfectly on his cock.

"Oh fuck," he moans as his cock impales Melanie's pussy. She is very tight.

"Oh Barry," she moans.

All he can do is lean back and let things happen as his sister starts riding his cock. She looks back over her shoulder at him, her normally sweet and innocent eyes filled with lust. She had turned into an animal, and it was an amazing look on her.

"Does it feel good?" she asked.

"Ohgodyes."

"I've never felt anything so big," she said. Melanie closes her eyes and moans as she starts cumming on his cock. "You're so perfect. I had no idea you'd been hiding that from me for so long."

"Sorry?" he said nervously as she rode him.

"You'd better be," Melanie told him. Her orgasm continued. "Oh, Barry. Fuck."

He can feel himself getting closer to cumming.