Okay, over the course of the last seven months I've had a fling with this chick. No reason to go into much detail. I met a guy through her social circle and he seemed like a pretty alright kid. Awfully beta, but nice kid. At least on the surface. We were chilling at some point together and he asked me what's going on with said chick to which I told him we're just having a good time. The conversation went deeper and for some reason I told the guy some interactions I had with her. Yesterday, we had a little argument and then all went out as a group. All of a sudden, the chick goes bitch mode at the table and starts asking "Who's fucked me in here without me knowing?" snarky type of shit. Then I catch wind that she's trying to prod at me and eventually figure out that guy sat her down and sprinkled whatever bullshit he's sprinkled on top of what I told him and basically turned her against me because I argued with him. I remained completely non reactive because I was already tipsy and the first thing that popped in my head was to go listen to my little caveman brain saying smack the living shit out of him, which isn't wise. I'm considering of calling her and asking what he told her in person, then proceeding to ask her if she believes him. If she says yes, I'll just cut the entire group off to avoid drama. If not, then I'll just start seeing the chick solo instead of the social circle. But I don't even know if this is the best course of action.

What the fuck am I supposed to do in this instance? It literally feels like a brick wall of a situation.

PS: Yes, I know, shouldn't have spoken to the orbiter.