Vampire Happening (1971) is a strange window into the 1970s
First of all, let's get this out of the way. There's a lot of 70s nudity in this movie. It's also billed as an "Adult Vampire Sex Comedy" so they really lean into it. Also, it's a low-budget movie from the 70s so expectations are a bit different. I can't quantify this as a "good" or "bad" movie, it's just an oddity in my opinion.
The movie is about an American actress who inherits a castle in Transylvania (pretty standard so far). She moves into the castle and learns she looks just like her ancestor, who was supposedly a vampire. The caretaker shows the actress the tomb where her ancestor was buried. She opens the tomb and finds her ancestor still looks exactly like her (hasn't decomposed) and runs away, leaving the tomb open. The vampire ancestor (played by the same person, of course) wakes up and climbs out of her tomb. Then we have a lot of wacky misdirection where the human actress and vampire ancestor constantly swap places to seduce/bite men in the village.
Anyway, the