No doubt defying logic...but who is really going to act logically in that situation when they first get hit with it?
The one time I know for sure of someone cheating on me, I found out months after we broke up. It still hurt like hell, but i was actually glad for the bit of knowledge because it allowed me to let go of whatever feelings I still had for the guy. Doubt she knew, either. I can't say 100% I wouldn't hate the ever living hell out of a woman who knowingly got involved with a bf of mine if I was still in that relationship and fully invested, though. I probably wouldn't lash out because I have this thing about my pride (big emotional scenes are not my deal), but the anger would probably burn a hole in my stomach.
Off topic, yeah, but the thread wasn't exactly going in a cohesive direction anyway