Nerdiest joke I've ever made:
B^k: (reading Empire article about how maybe Anakin goes to the dark side because he can't get it on with Amidala) But they have to shag, don't they? To conceive Luke and Leia. Will they shag in this one or the next?

Me: I think this one. Because they'll have to end three with separating the twins, and if they're conceived and born in the same movie, that's a lot of stuff happening.
B^k: Maybe they don't shag at all, and Anakin gets pissed off about it and just impregnates her anyway. Use the Force! Hah!

Me: These aren't the sperm you're looking for?
B^k: What about: "These aren't the eggs you're looking for."?

Me: Jedi contraception!