Purple caped vampire

Older vampire film. Classic time frame. 1960’s, 70’s or 80’s

When horror was super sexualized. Vampire with a purple cape (maybe). Mesmerizes a young lady, who swoons prone on the bed. Vampire bares her breasts and drags his fang down one breast. Drawing blood as he moves down to finally suckle her nipple. Despite that graphic scene I really don’t think this movie was billed as porn. Forgive me if I’m misremembering.