I am not a huge fan of a few things that my ex enjoyed. I did them because she liked it and because she did a few things that she did not particularly love.

1. Being caned. I am not a fan of the cane. I can take a little bit of it but it turns into a kind of pain that I am not big on.
2. Enemas. I have a love hate relationship with them. Before hand, the thoughts of it really turns me on and even during it its great. But what goes in must come out and I am not a big fan of that part lol.
3. I don't like severe testicle pain. I don't like being kicking in the balls or any kind of ball crushing. This is a hard limit for me. I don't like the kind of pain that makes me sick to my stomach. That having been said I do enjoy CBT just a more tame form of it.