I find it very odd that person would be more comfortable witnessing a 'prison-rape'-type scenario...
Well, I should put it more context...
When I was in college some people I was friends with wanted a bunch of guys to watch homosexual porn so that they could then comment on our reactions for the purpose of some paper they were writing.
So, we watched some porn, and while it wasn't exactly comfortable, it wasn't quite as squeamy is two guys kissing. I think maybe it's less about"domination" and more like Shuma is saying, if it's sexual, it's less upsetting cause people do odd things for sexual gratification, whereas real affection is more "pure" and thus more upsetting when done "wrong."
When you put it as you have, yeah, I don't think I'd be very comfortable with rape type scenarios, probably much worse than two gay guys kissing.
Altho,
FWIW, the porn that we were shown in the aforementioned college experiment was a bit "coercive." It was a "hey, you have to do xyz if you want to be on the tennis team" sort of scenario, so one guy was being "coerced" by the other.