"That's a real beauty," she whispered. "I'll bet you have fun jacking it off."

Billy was too embarrassed to speak, but he was sure enjoying what his beautiful big sister was doing to him.

"Does that feel good?" smiled Heather as she began teasing the foreskin up and down over his pink cockhead.

"You better be careful," he panted. "Or you're gonna make me shoot goo all over you."

"Penny," she whispered, ignoring his remark and reaching for the cute girl's hand. "Touch his cock and see how good it feels."

Penny's heart was pounding wildly in her breast when Heather wrapped the pretty youngster's fingers, around Billy's stiff hot prick. Penny had been secretly wanting to see and feel a boy's cock for months, but she didn't want to admit it.

"Slide the skin up and down," Heather suggested. "Boys love that."

Penny's virginal cunt was getting all hot and itchy as she excitedly stroked the hot hardness of Billy's rigid prick.

"Does ft feel good, Billy?" Penny asked as the boy leaned back against the sink to steady his trembling legs.

"Jeez, yes," he panted. "It's neat!"

"That's enough," said Heather a few moments later, not wanting her brother to shoot his wad yet. "I think it's time to let Billy play with your titties."

"But, Heather!" gasped the girl. "I can't let him do that!"

"Why not?" laughed the older girl. "He let you play with his prick."

"But that's different," Penny argued.

"No it isn't," Heather persisted. "Take your halter off."

"Oh, gee," the young man blushed. "I just can't do that."

"Billy," said Heather, turning to her brother. "Wouldn't you like to play with Penny's tits?"

"Sure," he grinned.

"Now stop being silly, Penny," the older girl said in a stern voice. "Take your halter off."