Oh I agree...whatever 2 consenting adults do behind closed doors is their business.
I had a friend who acted out rape fantasy w/ her then boyfriend (now her husband). The line was so blurry that even afterwards he was concerned and kept asking her if he had just raped her. I would assume that a safety word should be put in place for something like that...so the guy would know if the resistance was part of the game or real...wouldn't you think???
That's the thing too, it must be quite difficult for some men to act that out.