Anything to do with Rape, incest & bestiality is something I stay VERY far away from. I don't even bother to find out if it's real or not...It's not something I would endorse. Personnaly it makes me sick and I have a hard time understanding how someone could get off on it.
There are limits and plenty of kinky stuff you can do without crossing that very fine line, but hey, that's just my opinion!