I once asked an online friend of mine what was it about vampires that appealed to women so much.
She basically replied that vampires are a no-frills masculine figure that could take whatever it wanted by force without actually hurting, and that the whole act of blood-sucking was an allusion to penetration - essentially, causing pain and pleasure at the same time on a tender spot.
So getting bit in the neck doesn't hurt?
I hope your friend will forgive me for not wanting to try that out.
Personally, I like this interpretation best.
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She drew a parallel about the strength of vampires being subtle enough that they could just pin you down without actually straining themselves before they got whatever they wanted out of you. Besides, according to plenty of vampire myth, the "kiss" is actually as pleasant as it's supposed to be painful, so... *shrug*
And yeah, that used to be my interpretation too, but them wanting to be fucked in the neck makes more sense to me. After the boob-job and the armpit-job, the neck-job!