You decide to see how she reacts to having nipples instead of an ass, it would be funny to see her freak out. So you push it, and only she becomes aware.
(Woman's point of view)
(Her name is Gabrielle)
I was walking down the street and then all of a sudden something felt weird. My ass felt... lighter. I decided to think nothing of it, as I would look later once I got home.
Later, I walked up to my apartment, and walked up the stairs, I fumbled my keys a little and unlocked the door. I instantly striped off some of my clothes, and found that my ass had definitely gotten smaller. So I look in the mirror-AND FIND TWO WHITE NIPPLES INSTEAD OF MY LUSCIOUS ASS! I started to freak out but thought there would be an explanation for this. But then a thought crosses your mind...