I heard how she was dyking and fukking multiple dudes. Stuff like that. My friend used to talk to her best friend, which I knew as well and she said they fell out and now she was a lesbian dating some chick.
Reminds me of a similar situation I was in. In my experience, she still figuring herself out. Unless she shows actual ability to better herself your boy is just another lesson. The other dude should allow his friend to make his mistake. But he's smart to keep out of it.