Vampires have blood, which is what's used to fill those erections generally required for sex, in their system only after they've hunted and sucked their victims dry. Everybody knows that. We also know that whatever Edward hunted was some strong stuff because if the new B.D. trailer is any indication, we're talking earth-shaking, headboard-busting vampire sex.

Don't buy that theory? Fine. Let's talk venom.

Instead of blood, vampire veins can sometimes flow with venom.  And if venom holds the power to turn a human into a vampire then let's be real, it can probably give the youngest Cullen a major hard-on.

We can only imagine what the Cullens were taught in Vampire Sex Ed, but maybe Edward should have paid closer attention, because the sparkly vampire went and got his new wifey seriously knocked up. How?

All vampires were once humans, and their body's state when they made the change remains. Read: Edward ain't shooting blanks and Bella still has the eggs for them to make a nice little half-mortal, half-vampire spawn named Renesmee.

But the point remains: What the hell powered Eddie's johnson so he could gift Bella with his all-powerful seed?

A vampire implant of some kind? No, this is sophomoric Stephenie, remember, not archly gifted Anne Rice, so your guess is as good as ours.

Which theory do you buy? Sound off in the comments!