I’ve always interpreted that feeding was their way of experiencing something akin to sex but somewhere beyond it as well. “The Kiss” wraps all their passions into that singular act.

Vampires have no sexual drive per se and I’d imagine next to the taste of another’s blood it has only tertiary pleasures. I don’t imagine vampires orgasming themselves since all their biology has shifted to the unending thirst for vitae.

Vampires can fall in love in a way but get their “sexual” release through blood bonding. That in turn converts the love into an addictive obsession because you kinda know you’ve trapped yourself. Like falling in love with something absolutely addicting and possibly very, very bad for you but you’re locked in and can’t stop.

Just like love among humans can be equally addicting, obsessive and terrible for you. How many past relationships do you look back in and think “what was I doing!? That was a terrible relationship!” Blame the addictive nature of your hormones flicking on to someone that’s close and familiar. Now thing vampire level addiction! Consuming on every level.

Vampire-human sex is probably an exchange of favours more than anything else. You give me vitae, I give you sexual opportunity with me. For a vampire it might be like foreplay, infusing the blood with a Resonance or Dyscrasia, thereby creating heightened pleasure and a lingering effect.