Why are some so EXTREEEEEMLY Perverted?

I have shared some notes with a few ladies that have had the extreme sexual perversion with their narcs; I am aware they all enjoy degrading their partners as much as they can - but still some are not so sexually perverted as others - Perhaps this is just a variance to the different types - your average narc will cheat and carry on many different relationships at the same time and even the women that have been the "other women" have reported there was no extreme perversion - I really know how to pick em, if it werent for bad luck I wouldnt have any luck at all lol - mine was so very twisted and perverted sexually - he would have screwed a ground hog if I brought one home; he reminded me of a porn director and we are talking triple X - into S&M, and god knows what else but thank GOD I didnt stick around to find out - any input from anyone who has done some research on this?