I went on a few dates with someone earlier this year but broke it off after various bits of evidence pointed to him not actually being single.
I didn't message his girlfriend at the time to tell her he'd cheated because, honestly, I kind of just didn't want to get involved. I figured I'd let sleeping dogs lie and let karma take care of him.
However, he's messaged me twice in the two months since we stopped talking. I shut him down and he goes away again. We didn't know each other before we went on dates and I have made zero attempt to contact him since we stopped talking, so he has absolutely no reason to message me except for attention/to see if I'm still interested.
I feel bad for his girlfriend. They've been together years and live together, so it's a serious relationship. But he's actively cheated on her and is messaging other girls (I'm pretty confident I'm not the only one).
I feel like if he messages again, I want to tell her. Three strikes and he's out. I don't know her, but I feel like she has a right to know what he's doing. If it were me, I'd want to know.
Would you message her of just leave it?