I do share porn with other guy friends (and a couple girl friends as well, yay women's lib). If I find something that I've really enjoyed, I'll pass the link along with the hope they get some enjoyment out of it as well.
But I'd never want to jack off with another guy. I'm not worried about what that means, societally or morally or whatever. I'm just not interested in watching any of my male friends jack off.
PS: Female friends though, if you're ever in the mood, you know how to reach me!