one more, then I have to go scrub my brain.

Quote from http://mendaredo.com/2011/02/05/penny-arcade-the-internets-and-homosociality/ (bolds mine):

I think we need to also have a discussion of what the rape culture means for men and masculinity. Rape culture is in many ways a manifestation of homosociality. Homosociality is the set of ideas or phenomena whereby men value relationships with other men above relationships with women.

Homosociality can be reinforced in many benign ways: men get together and watch football together (a thing that women can participate in), or say, go to bars with other male friends. But some of the most powerful ways to reinforce homosociality and to reinforce our relationships with other man is to engage in activities and behavior that exclude women, hurt women, or otherwise reinforce our masculinity.[...]

As the heteronormative narrative goes (which is crucial to understanding homosociality, as it exists within that context) rape is something that happens to women. It doesn't happen to men. It's something that bad men do to women. So

the act of making a rape joke is one of these ultimate homosocial acts, like street harassment. It's something to bond men to other men, and only other men. Women can't participate in this type of bonding, because rape is something that only happens to them and something that only men can do to women.