Don't get angry. Just be persistent and keep bringing it up. After class or in a relative 'debate' or discussion.

Then again it is a catholic school. And the teachers are in general usually more close minded.

How old is she? How religious is she?

I'd keep on trying to reason with her. But only to a certain point. Then i'd break it off by saying "How can i respect and therefore learn from someone who is...."...

Of course, you can learn from someone who is close minded, stubborn in beliefs and all that. But that isn't the point now, is it?..

But also you can see where she is coming from. A catholic school teacher. Female. And this man is using a woman's vagina and the woman herself as a metaphor for life. Of course we understand it. And appreciate the meaning. That part of it is in fact the opposite of what she is thinking. But with the stigma attached to Hip-Hop. From the countless lyrics and videos of many rappers in the mainstream. And then to hear that. It's easy to understand. Especially as she doesn't listen to hip-hop. But especially cos she doesn't know the characteristics of the artist.

Maybe you could enlighten her on who he is. And some of his other work. That he is in a sense the 'brighter' side of Hip-Hop within the context she sees it.