Michael's sister Jean in a foursome!

Michael couldn't believe the scene unfolding before his eyes. It was unlike anything he had ever seen before, and as his stomach churned, he wished that he could have never seen it at all.

The four of them, Jon, Cassandra, Lily, and Jean, were close together... very close. Jon was standing up straight in the tub, his naked body mostly out of the water. He had a satisfied look on his face that Michael despised. Cassandra was naked, too, and pressing her enormous breasts against Jon's chest as she kissed his neck. Jon was grabbing her ass, and from his vantage point behind the door, Michael could see that Jon had his fingers inside her.

Making things worse was the fact that Lily seemed to be fawning over him, too. She was still wearing her bathing suit, but she had pulled the straps down to expose her small breasts. She had one hand on Cassandra's ass, much like Jon, while the other was between her legs. She was pressing herself against him, too, like some sort of fucking groupie. Already, Michael was seething with jealousy-- he had hoped for a chance to hook up with Lily, and here she was, rubbing up against Jon like she was his bitch.

That jealousy became somewhat complicated when he realized who was between Jon's legs. Michael's heart dropped out from his chest, and his mouth dropped open. His older sister Jean, his parent's pride and joy, was bent over the side of the hot tub. Her eyes were rolling up, and her mouth was open in a long, contented moan. Jean's tits were pushed against the rim of the tub, and every once in a while when Jon thrust his cock into her, Michael could see his big sister's nipples. Her entire body was covered in sweat, and her hair was matted and messy, looking like someone had had been pulling it.

"Fuck!" Jean grunted.

"Yeah, fuck," Jon said, staring down at Michael's sister's ass as she slammed it back against his hips.

Michael had no idea what to do.