Sorry to be slow in getting back to you, Razor...

For me, just senseless violence can be a turnoff, yes. I'm not into snuff or extreme, gory torture. But the biggest problem I tend to have is with stories that portray women purely as objects, not as characters. Even if you're writing in first person from the tormentor's point of view, you can give the female characters humanity. Even a gagged person still acts like a person!

Basically, as long as your characters stay people, I'll forgive you an awful lot. It's when the sex partners start acting like the offspring of a porn star and a Real Doll that I get kind of offended and really turned off.