Sigh. This kind of sh*t is demeaning and emasculating, and why I don't trust broads much anymore.
If it ain't happening yet, they'll get a few drinks in them at some point, he'll make a pass, and she'll either deny or accept his come-on.
I would start running game on her immediately, going out and meeting chicks. If she questions you about just do exactly what she did.
Don't be as available to her. But start meeting other women now. I'm not saying throw the relationship away.....just be wary.
IMO, this is open season on you starting to at least talk to other women again. Escalate it exactly the same amount as she does.
Seeing as she is hanging with other dudes, you have full permission to start hanging with other women, and contacting them, and going out for drinks.