A young couple, Bill (William Howard) and Lisa (don't know who plays her, but she's a hottie), decide to spend a couple of days of their European vacation in a haunted castle, unaware that the owner (Bambi Allen) and her other guests are devil worshippers.
Terror At Orgy Castle: what a great title - shame that it's wasted on a dreadfully dull soft-core porn flick with mild horror trappings, a film made all the more boring by a really monotonous voice-over (seems like director Zoltan G. Spencer couldn't be arsed to record any sound while filming and added the narration afterwards).
As far as the sex goes, there's lots of it, although it's a case of strategically placed limbs and careful camera angles obscuring anything too explicit (there is, however, absolutely tons of full frontal nudity from both sexes); the horror is virtually non-existent - certainly nothing to inspire any terror!