facials
As I was the one who started this thread, I thought I would put in my 2 cents worth just for the record.
I've only met 2 women in my life that would let me COF. Both were contacts (non SP's) I met through chat lines. They were both wonderful experiences.
I enjoy this particular fetish for a number of reasons. First, like almost every other guy in the world, I am very visual. I love to see my cum rather than just feel it shoot inside a woman. There is the added thrill I get from the contrast in seeing, first a woman's pretty face, and then, my semen covering that same pretty face (maybe a subconcious statement to all the pretty girls in high school who wouldn't give me the time of day).
That leads to the other turn on for me which is, yes, the dominant aspect of it. To put it bluntly, the humiliation effect. It is such a different way for me to behave. I am VERY respectful of all women at all times. This is simply a fantasy, to behave in a manner that I would not normally. It's like very dirty talk during sex. Calling the woman nasty names. I would never do that in real life, it's just something done in the heat of passion.
The aspect of having a woman "submit" to me ejaculating on her, whether it's on her face or breasts (which I also really love and have enjoyed with almost every SP I've been with) is the best of all worlds for me. It fulfills the experience of spoiling myself. I know it's purely selfish on my part, but then that's why we enjoy the hobby in the first place, right?
I think if the truth be told there are many of us out there that would like to do this but are too shy to even ask.
I hope I've articulated this in a reasonable manner. I mean NO disrespect to any or the ladies out there. If they choose not to do it, I can certainly respect that.
Keep smilin' 
