Not even that. Just realize that she wasn't the one or whatever. No man or woman should settle for the opposite sex if they're going to cheat on them. Hence why I left my whore...er...ex.

He's probably going to claim loving her cuz he's got a kid with her...well...halfway...

Either way. Fuck 'er if you don't have any ties (kids, bank accounts, etc) just say "Good luck to you and him. Hope he's worth it" and walk out.

Took nuts to walk in, though. Especially to not just walk in and deck him, LoL.