My own various takes are these:

I have always been horrified at the though of a man raping a woman - if that's cultural, it is persistent.

I used to be horrified by gay sex in either direction, but no more - cultural.

I really can't envision a woman raping a man (or boy), so I guess that's not cultural?

The idea of anybody forcing sex on someone who is not willing is abhorrent. All I know is that my equipment would not be functional in such a scenario.