<human>: Long time lurker, first time poster. Hi. 

I met this girl, Amy, on okc & we've been seeing each other since October. Nothing really serious, but I'm just coming out of a very abusive long-term relationship and a lot of her behaviors are reminding me of my ex. There are a lot of red flags, but the biggest one is Karen.

Karen is apparently her long-distance girlfriend living in Chicago for school. I didn't know about Karen going into the "relationship" but it didn't bother me because I assumed (somewhat naively) Karen knew Amy was talking to other girls. Recently, though, every time I'm with Amy & Karen texts her, she'll ignore her phone in favor of me, or lie and say she's not with me. When I've confronted her (which I have multiple times), she gets defensive and asks why I care about Karen... which I have explained to her. Being cheated on SUCKS, and I told her that if she is making me "the other girl", then I'm out of there. She insistes that Karen knows, though, and that she is okay with it.

Amy is flying to Chicago to spend the last 3 weeks of the year with Karen. I'm not sure what to do. My options are to pretend it's fine like Amy says, end things and tell Karen, or just plain end things and let Karen stay with someone I know is a liar.

Give me the gist of the text in a nutshell
<bot>: The girl I'm seeing has a girlfriend, is lying to her girlfriend about me, and I don't know what to do.