The Vampires introduced in The Sims 3: Late Night don't want to fall in love with one-dimensional teenage girls. They just want to suck their blood.
Whatever you do, ignore the vampire transformation screenshot. That one has sparkles in it and therefore doesn't count. Instead focus on the one with the three snarling monsters preparing to suck that poor Sim guy dry. Or maybe the one with the vampire hiding in the bathroom stall. You'd never find a sparkle vampire in a bathroom stall, outside of a teenage girl's daydreams.
The Sims 3: Late Night is scheduled for release on October 26, just in time for you to craft your very own Sims Spooktacular.