You decide that you would use this spell on your girlfriend, I mean how cool would it be to have a cow for a girlfriend that can easily orgasm!
When you call her you say, "hey Rachel get over here now I have something to show you!"
When she finally gets over here you say to her, "bovinus transformus " and she yells out in pain but looks everywhere but she can't find what was painful. Then she notices that her gut is hanging out. She thinks," I'll just work it off in the gym" and she realizes that she has a sudden urge to tie her clothes off. But she couldn't because she doesn't want him to see everything yet...
The changes continue