Were Species 2's nipple tentacles not enough for you? In that case, there's always Thralls aka Blood Angels, which features ultra-convincing CG snakes coming out of a woman's breasts and biting a man in the neck. It's just possibly NSFW.
Somehow we overlooked this gem during both CG week and our roundup of scary sex scenes. We're even more embarrassed that we somehow missed this great moment of terrifying fellatio:
In Thralls, a group of five women are neither vampire nor human, cursed with the need to feed on human blood but unable to turn others. And they need to become free from their demonic master — so they open an underground rave club. You know it makes perfect sense. Thanks to Madeline Ashby for suggesting this one!