conclusion = the angry guys are only mad because their girlfriends in the past cheated on them.
your point?
it's a shitty practice. Especially if you know the dude, or the dude is your friend (i don't care how close you are you don't do it anyways)
bros before hos. if your dudes girl is a ho, don't exacerbate things. you only hurt yourself, and your dude. and seriously fuck the slut for coming on to her boyfriends friend.