I think you mean the "enjoyment/motivation dichotomy" or the "wanting/liking dichotomy". Many sexual masochists report a sort of euphoria and dissociation that begins to arise after a certain amount of pain, which would seem to be a positive liking. Many also report a positive thrill from humiliation that might be considered to overwhelm the negative parts of the experience. (I think pretty much all report that if the same things were to happen in a non-role-playing situation, they would not like or enjoy them. But it's hard to test that.)