I would definitely try to convince her not to go through with it. It's one of those situations where she'll be wishing she hadn't of went there.
Yeah that's a 10-4 on the stay away suggestion. Do not engage! If she were to screw the guy then she'd be living with an ex-boyfriend, his cousin who she had a fling with, and the girlfriend who probably hates her to the core after that. Honestly, if I was in her situation, I'd deal with the girlfriend and just move out.
