The Velvet Vampire (1971)
It's hard to imagine a vampire menage a trois being boring but "The Velvet Vampire" is a long time between good bits. There was a suspenseful rattlesnake attack, some excellent bat-on-a-string work and nude vampire sex scenes, but it moved at the speed of a drugged diplodocus. The music reminded me of the stoners I used to hang with in Ballarat.