Marla watched, her chin on one of her son's knees. The sight of her daughter's pink cunt clutching her son's cock created an intense desire within her. She tickled Bob's balls with her fingertips, pressing her lips to his knee. She swished her tongue along his thigh, her eyes never moving from Sally's cunt riding that cock.

Juices from Sally's tender pussy began to collect at the base of his cock, and Sally squealed with rapture as she began humping up and down, the cheeks of her pretty, tight ass bunching and clenching. Marla stroked her daughter's shaking ass with her other hand, gripping her son's balls, twisting them. She slipped her fingers underneath Sally and rubbed them along her stretched cuntlips, feeling her son's cock go in and out. She drew her finger back, looking at the wetness on it. She pulled the finger to her lips and smeared them with the tasty juices of Sally's cunt.

With a moan, she released her son's balls and drew her hand to her face. She licked her palm then cupped his balls again. She burned wet kissed about Bob's thigh, her eyes constantly watching Sally's cunt pounding up and down his cock. Bob was gripping his sister's tight ass now, arching his cock upward, groaning with the fiery tightness of his sister's pussy.

"Oh, God, that's beautiful!" Marla cried softly. "Ohhhh, fuck that hard cock, Sally! Your cunt is so full of that cock! Fuck him, baby! Fuck your brother hard!"

"I am!" Sally sobbed, her ass churning, humping and thrusting. "I am fucking him, Mother!"

"Bob, your balls feel so full!" Marla hissed. "Give your sister a big, hot lead of that sweet come-juice! Her cunt is so hungry for it!"

"Go faster, Sally!" Bob was groaning. "Go faster!"

Sally fucked as fast as she could her tight ass jerking back and forth, her clit sliding on his throbbing cockshaft. Marla clung to her son's balls, her eyes glazed with passion. Her cunt was sucking inward, her clit bulging very hard. But she held her son's balls tightly, running her other hand up and down Sally's shivering, smooth thighs, her hips, urging her daughter to greater efforts.