biff let go of jon as he started to slide towards Wendy and she slid towards him, their bodies pushed together and started melting as they flowed into each other.
When it finally settled Jon was shocked to see what looked like Biffs muscular body with wendys hair, freckles, glasses, and braces. He had her small breasts, skirt, and blouse but otherwise looked like biff, even down to the bulge in his panties revealed by his lifting skirt. The more massive body must have won out, but did their minds merge, and if so does he/she want to love jon or hurt him.
Biff/wendy did a hesitant step towards Jon and started to say something...