Boom. If they cast a spell they'd actually change sex just like they would actually turn a person into a crow or a snake.

But then there'd be no controversy. That person IS, as a matter of fact, the thing they changed into.

They actually enjoy the idea of pretending to be something they aren't and then either A) getting everyone else to knowingly validate the lie. Or B) you don't acknowledge them and they play the victim.

Either way they get attention and try to make others endure a humiliation ritual.