Suddenly Joce nearly doubled over. Her pussy ached horribly- in growing her so mature and well rounded (at least in certain places) she'd become overly sensitive! Just moving was driving her towards exctasy, but it stayed just driving her over the edge. She whimpered, and shot Peter a desperate look. "Peter, I need you now!"
Peter looked around them, at the empty back alleyway. Sure it was deserted, but it was still kinda in the open. "You mean you want me to-, out here?"
The older Joce shoved her panties down and ground her hips against his jeans. "NOW."
Peter fumbled with his zipper before rubbing a hand against her clit and labia. Spreading the thick lips wide, he shoved home, feeling himself swallowed up by the giant cunt he'd created a minute before. He tried to see towards where he was working, but instead was greeted by a wall of flesh that was Joce's breasts, like a giant pillow between them. Not knowing what else to do, he grabbed each one in his hands, stroking the visible skin. They jiggled in his hands, and he could feel the large nipples harden through her dress and his shirt.
Joce's eyes rolled back with pleasure. "Oh, wonderful. But...not...quite...enough..."
Peter was dimly aware of the tingle of transformation through his own desire. Then he could feel his dick expand rapidly. No longer was it loose inside her giant pussy, it pumped to the size of beer can, then twice that, and belatedly he realized his head was hitting her upper walls. He surged a little further, and now to him she was incredibly tight, stretch a bit with each thrust.
Her giant watermelon tits bounced into his face, and he greedily popped one out of the top of her dress to suck on the engorged nipple. Sweet milk filled his mouth, and she screamed and clamped down, reachin her orgasm.
It drove Peter over the edge, and suddenly the feeling of transformation engulfed his entire body and he began to change...