I was at a museum of erotica in Copenhagen once and in the porn section they have a room with the more extreme stuff, not for the fainthearted. I just stuck my head in and caught a few glimpses of a screen with a girl giving a dog a blowjob, and I'm sure there was other more disgusting stuff there too, like waterworks, scat play, etc. Oh, and some of the heavy s&m stuff I find really disturbing... I can't think of anything really bad right now but even things like nipple clamps make me a bit sick to my stomach.