Looking for the name of a Vampire movie

I can only recall one scene from this movie. A guy comes in from off the street, and a female vampire seduces him into her hot tub or pool. Just as shes about to do him in, someone knocks at the door, so she paralyzes him, by biting his you know what, and then drowns him. As she pushes him down under the water she tells him something like, "your better off dying this way" or something, then she goes and answers the door.

Does that ring any bells to anyone???????