When I found out a boyfriend was cheating on me, I went berserk, but I didn't beat anyone to a bloody pulp, lulz.
I hacked his email, found the messages and meetup plans he'd made with her, emailed her and introduced myself, thereby destroying their little side-fling, and then forwarded them to his father (who I was friendly with) because I went extra cray. And then I called him and screamed that he was a whore for a half hour.
We eventually got back together, haha.