The worst is if you're dating someone for a bit, the sex is good, things seem to be moving along ok, and then something you could have gone your whole life not knowing slipps out and ruins it. Usually because she or a friend is too drunk, then you (me at least) just gets quiet but not pissed or anything because confrontation sucks if there's no winner, they are still drunk and press the issue until you lose patience, and then you just blurt out that you don't make a habit of dating girls that have been gangbanged in the middle of a party, and suddenly you become the asshole.