In a medical scene or setting, if I am being masturbated by a doctor or nurse, male or female, I feel somewhat submissive. I know I could get up and walk out, but I'm letting them do that to me for some reason.
If I'm getting a handjob from a woman outside of a medical situation, it all depends on how she plays it. If she gets aggressive and wants to slap it around a bit, or tie it up, or just go fully to town on it, well then she's in charge. I'll beg her to stop or just keep my bitch mouth shut. If she wants to play innocent and shy, then I'll shove her hand down my pants and tell her exactly what she is to do until she begs me to shoot my load all over her. I really like making them tell me where on their body they want me to shoot it.
It took a long time for me to get comfortable letting guys beat me off, and at first I was only comfortable doing it in med-fet games, and only with my girlfriend present. I'm now able to enjoy it without the medfet part but I do still enjoy other people being there, and I prefer to be fully nude, but I do feel 100% dominant. I'm letting this guy beat my big dick off in front of his wife, or my girlfriend, or some strangers at a party.
I'm pretty tall and pretty built, and in ok shape generally. I'm no athlete, nor a model, but in a small group of people, the odds that there would be another guy there who could believably, physically, dominate me, if we wanted to play that way, are slim. I wouldn't know where to begin.
On the other hand, I did spend most of high school begging girls to touch it, so I'm already pretty comfortable with that dynamic.