Clitoris

You smile broadly. You've so got this. "It's the clitoris."

"You're correct Amber! John, if you would please strip and enter the programming chamber."

John strips off all his clothes. His body isn't much to look at, but you smile as you realize the change that is about to come over him.

"Now, the first level of programming is appearance. A specific body type has been chosen that will make Amber positively wet with anticipation. This machine will transform your body into her ultimate fantasy!"

John is locked in place and the machine starts to make noises, changing his body.