I did a little rant kind of about it in this thread:
https://www.buffy-boards.com/showthread.php?t=18430&highlight=vampires+sexy
Here it is:
Joss said, and I agree, in all horror films the demons, monsters etc are representations of sexuality. Think of warewolfs, the first one we see is Oz and it represents the stereotypical males, unruly, passionate, animal, savage etc. When we see Veruca she is completly into the wolf thing, unlike Oz, and is far more sexual and deviant.
Vampires themself are seen as sexy because they are immortal, wise and without a soul, meaning without feelings of "right and wrong". Vampires can do something that is normally seen as sexually taboo so it brings about this whole different level to them, they are more free then humans. This immediatly makes them more sexy, even if its not our thing the whole open and able thing is rather erotic and could be a turn on for many people.
They are also passionate and for most vampires there is something there and a reason why they bite or sire someone. Most of the male vampires only bite female ones because it is seen as a sexual act, while they do sometimes bite males it is rare or for other reasons, such as trying to make a vampire army. Female vampires however bite any sex, which is an interesting reflection of humans. Men are a bit worried and edge away from things that may be seen as "gay", although this could be due to social pressures saying this is a terrible thing and the whole 'insults' of "you're gay" when growing up. However women are far more open to holding hands, hugging etc other women as it is just seen as friendly.
The whole siring thing is seen as sexual and is a nice metaphor for sex, the whole exhanging bodily fluid things. When we see Darla or Dru siring they cut the skin above their brests, which is rather overt. However something I realised, the way vampires sire is also kind of how humans get AIDS, so vampyrism can be seen as a STD (okay so thats not sexual but its about sex)
