Naughty vampire question
Here's an R-rated question I'm sure has been much discussed in the Buffy fandom, but which only occurred to me the other day: since vampires have no heartbeat, their blood must not circulate; therefore, how do male vampires, you know, perform? I gather that they do, what with Angel's angst over his physical relationship with Buffy; not to mention all the kinkiness hinted at by Spike and Drusilla. But how?