A lot of people find the idea of Sex with a female vampire to be a very attractive one. The truth would be a very different story however as Sex with a vampire would likely lead to death. People allow themselves to become charmed by the ideal and less by a reality if they were to really exist.
The vampire is a killer, it is a serial killer, and the one thing it certainly isn’t is someone that you would want to fuck regardless of how attractive they were. They exist only to feed and even under the best of circumstances would it find it extremely trying just to keep their desires at bay. The problem has come from too many writers turning the vampire into a heroic sort of character and one that people adore. This flies in the face of their and truer and more natural state. Even a vampire with the very best of intentions would find it tempting to eat their professed friend. If a vampire really existed in the modern sense of the creature they would be almost animal like in their habits. Most of their waking hours would be spent on the hunt and either feeding or setting up an opportunity to feed. Then they would be off to their safe place to rest and recuperate until the next time. Contrary to what most people believe they would not spend a whole lot of time waxing poetic about their existence. They wouldn’t have time.
Another fact would be their physical state. In order to survive on a strictly blood diet they would need to consume a tremendous quantity of blood and this would likely leave corpses all over the place. They wouldn’t likely observe such niceties as taking just a little and leaving the person alive to tell about the tale. Then there would be the consequences. With that many people dead in the area it wouldn’t be long before a hunt for the hunter would be on.