Physical & Emotional Abuse Support Group
Abuse is a general term for the treatment of someone that causes some kind of harm (to the abused person, to the abusers themselves, or to someone else) that is unlawful or wrongful. No one deserves abuse, period. Abuse can be emotional, physical, or sexual.
If it's been 3 times, I wouldn't be surprised if he isn't also flirting with her to get information. Heck, just to piss you off, he might have an affair with her. If I were you, I'd definitely "shelve" that friendship.
Regardless if she's falling for all the charm, or whatever, she's still knows how this is effecting you and doesn't care - that's obvious by her behavior. Something like this can only get worse - I can only imagine the things he's telling her about you (working on an ally) and HE KNOWS his "visits" with her are going to get back to you.
It's all a game. It always is. Let her be the sucker (sucker because she knows about him and you) and protect yourself from both of them. That's what I would do, for what's it worth.
Good luck hun!
I hope that she realizes what she is doing to you.