Julie darted a hand behind her son's plunging ass, between his legs. She grabbed his balls hard just as he slammed his cock urgently into his sister's gripping, convulsing cunt.

"Give it to her, Ben!" Julie gurgled, feeling her son's balls writhing in her hand. "Shoot it up her little cunt! Fill her pussy with come juice, baby!"

Ben was grunting with each gush of his come juice, his cock deep. Julie felt his balls empty, and suddenly there was a squeal from Becky, a different sound.

Piss gushed out of Becky's pussy. Julie gurgled as she saw Becky's piss splash at her son's lower stomach, spraying outward. She slammed her free hand between her thighs as an orgasm exploded in her cunt. She hissed with delight, eyes blazing as she watched Becky piss, gripping her son's balls tightly, the heel of her hand grinding at her convulsing cunt.

"Oooo, look!" Julie hissed. "Oh, God! Becky… oh, Becky!"

Ben had been too startled to say anything when his sister began to piss, and Becky was expressing embarrassment. At that moment, the only one showing excitement was. Julie. Her eyes, big and bright, blazed hotly as Becky tried to stop pissing. The more she tried, the harder she pissed. The hot piss came in quick squirts, splashing at her brother's body, spraying past his hips.

Julie squealed with perverse delight, feeling her daughter's piss running down over her son's balls, and on her hand. When the explosive orgasm faded, she pulled that hand from her thighs and placed it on her daughter's stomach, her fingers close to the stretching pussy lips. While her own cunt kept convulsing with milder contractions, Julie pulled upward at Becky's cunt, wanting to see the golden piss spewing. A short squirt of piss came out, ran over the base of Ben's cock, and then Becky got herself under control.

"Ben, I didn't mean to do that," she said shyly as he pulled his cock from her clamping hairless cunt. "It was an accident. Ben. I'm sorry, Ben."