I don't cum simply from being tied up or spanked. Hell, for me, cumming is never simple. *lol* However, I am turned on by domination, fear, humiliation, and pain. It doesn't even have to be "fun" for my juices to start flowing.

You might just be a kinkster, and there's nothing wrong with that. People do some of these things for fun and to spice up their sex life, like my best friend. People like me do it because "normal" sexual activities are not very arousing. Too many times in a row of regular ol' sex without a spanking or some other such activity will result in my inability to cum or even to get wet or stay wet. In fact, I'll get distracted and start thinking of something else, wishing it would hurry up and be over.