Castiel: It does present a curious curl in the metaphysics, doesn't it? If you murder a monster in monster heaven, where does it go?
Benny: And this is the crazy aunt I want to take on the road?
Castiel: I am not your aunt.
Benny: What? Really?
Castiel: I have no possible relationship to your sibling offspring.
Benny: Now you're kidding me.
Dean: Oh, you two are killing me.