Not so much into the SM part, but I definitely think there is a BD aspect to my CDing. And it isn't so much "submitting" like a servant or slave, but more being served and allowing your partner to take the reins. This thread is about sex, so I hope no one objects to me getting a bit specific in my descriptions that will follow... if you don't want to read it, go ahead and skip the rest of this post...
No matter how you cut it, in the end, a man's penis really is in control, whether he wants it to be or not... There have been times that it is hard to hold back an orgasm, which makes it hard for my wife to "take control"... I would have to tell her "I'm ready", which still has me in a degree of control. So that may be some of what is causing me to desire taking a more submissive role, because it is so hard to be truly submissive.
I envy my wife being able to orgasm over and over and she really seems to get "lost" in the feelings, sensations, and emotions of the event. I have to finish and then I've got to take at least a 15-20 minute rest (if I'm able to go again at all... usually only with the help of an "enhancement" pill). And it isn't a "lasting" issue... I can last just fine. It's that at some point, I decide when it's over. That is sad to me.