Carolyn glanced over her shoulder at her mother then turned her eyes away swiftly. Bobby had fallen to the floor, rolling about and giggling.

"Your ass is showing… your ass is showing!" he said over and over.

"Your ass is gonna be showing next, you little shit-head!" Carolyn threatened, falling on her brother and wrestling him about.

Lynn stood still, surprised that her cunt had suddenly started steaming. She watched Carolyn and Bobby thrashing on the floor, rolling over and over. Carolyn's pretty ass cheek was showing again and again, and Lynn noticed then that her daughter was struggling to pull Bobby's pants down. He was hanging onto them for life, laughing with pleasure. Carolyn sat on his thighs, jerking his fly open and trying to pull his jeans down. Lynn found herself staring at the white of her son's jockey shorts, knowing she should put a stop to this.

"There! That'll show you!" Carolyn yelped in triumph, jerking her brother's jeans to his thighs.

All sounds stopped suddenly. Bobby was no longer trying to get away from his sister. Carolyn sat on his thighs, her eyes hot. Lynn felt her legs tremble.

Bobby's cock was outlined by his jockey shorts and it throbbed visibly. He had a hard on and the head of his cock was molded by the stretching shorts. A moist spot formed where his piss hole pressed and the crotch of his shorts was filled by his young balls.

Without warning, Carolyn slapped her fingers lightly across Bobby's swollen cock.

"So that's why all those girls at school call you hunk. I can see why!"

Lynn's eyes became glassy and she had to struggle to stop looking at her son.

"That's enough you two," she said, unable to keep the tremor out of her voice. Carolyn lifted up from her bothers thighs, but she still stared at his cock. Bobby got to his feet, holding his jeans in one hand and starting up the stairs.