After seeing Teeth:

Andrew: Thanks for never biting me with your vagina dentata.
Me: Oh, Andy. If I had teeth down there, I'd never use them on you.
Andrew: You might. You can get pretty peeved during sex.
Me: That's true. I get worked up.
Andrew: I'd go to the doctor, and he'd be, like, "What did I tell you last time? She doesn't like it when you do that!"
Me: Wait. Are you picturing this happening multiple times? I'd bite your penis off with my vagina, you'd get it stitched back on and come back for more?
Andrew: I assume so.
Me: That might be the most romantic thing you've ever said to me.
Andrew: Well, I don't want to be a quitter.