Vague is fine. Though it's worth pointing out that even with Slaaneshi demons, any sort of orgy would very very quickly become something more like a charnel house snuff film. They want souls, and the quickest way to get them is by killing people; the lust is just a lure to get people vulnerable, rather than an end goal in itself. Their victims die in exquisite ecstasy as demonic claws simultaneously disembowel them and brush against every pleasure nerve in their body, but they die all the same.