Orgy Isle by Don Elliott; Robert Silverberg

VAMPIRE WOMEN! He was washed ashore on an island of women. No man had been there for years . . . and each hungry wanton was impatient for her number to turn up for the game of shame and degradation. Even though it could mean their death to be discovered . . . still the urge to passion was so strong for them that they could abandon their nightly rituals of dancing around the fire to worship the evil vampire bats . . . nothing was too much for them to risk for a single moment of ectasy in his secluded love cabin high on the hillside of shame . . .