In spite of himself, Paul felt his cock begin to grow hard. He looked at his little sister. God, not little anymore! Why is it I haven't noticed until now, he asked himself? God, those firm, ripe tits! The long blond hair, that sweet, angelic face!

"I don't think so," he said. His tone was, "Yes, I want it too!"

"Show me your dick," Robin begged. "Let me touch it, please?"

Confused, but excited, Paul unzipped his jeans. His large, pulsating cock flopped out, bobbing against his stomach.

"Baby sister, you don't want to do this," he said, resignation in his voice.

"Yes I do!" Robin said, clutching the thick shaft with both hands. "Oh God, yes I do!"

She leaned over and clamped her mouth around the thick, round cockhead. It was everything she thought it would be! Hard and yet soft, deliciously fragrant and heady. She pulled his foreskin down and darted her tongue around the indentation below the end of his prick. Her senses were immediately inflamed by the flavor of dried cum and piss. She moaned a soft gurgling sound.

"Please don't!" Paul whispered. "Robin, don't do this!"

Heedless of his request, Robin gobbled this long, hard dick hungrily into her mouth. She almost gagged as the round ball of his prick stabbed against her tonsils, but she didn't care if she choked to death. All she wanted, was to have that beautiful, delicious prick embedded inside her mouth.

"Please, Robin… don't… oh God, Robin," Paul moaned, unable to believe his sister's hot, sucking mouth. "Please!"

Robin cupped his firm, cum-filled balls, gently rolling them around on her cheeks as she had seen Gina do. They vibrated with life, filled with a thick, lava-like load of creamy cum.

"I will never stop!" she gurgled, her voice-box pierced by his throbbing dick. "Never! Never! Never!"