I tried to explain to a friend of mine years back that the girl I was seeing was a sadist. He didn't understand the term so I explained it to him. Then he asked "So what does that make you?". I told him a masochist. He didn't understand, so I broke it down for him again. He wasn't that bright, and wasn't a great friend, but I wanted to tell someone about the amazing relationship I was starting. He looked at me blankly, "So if you like stub your toe or step on a thumb tack, you get a hard-on?". I sighed. He couldn't understand the concept of context. He assumed that if I enjoyed pain at the hands of a woman, that I enjoyed pain in general. Since then I've kept my thoughts on BDSM between my girlfriend and I. Ever have a problem explaining your masochistic tendencies to lay people (for lack of a better word)?