<human>: My girlfriend and I have been in a relationship for about 3.5 months. When we first started hanging out, she had a boyfriend. I had no intention of stealing her away from. At the beginning, all I really wanted was a friend.

As things progressed, and her relationship got sour, (It had already turned before I met her)  my feelings grew stronger. We ended up going to the bar one night with a bunch of mutual friends and one thing led to another. There I found myself letting her cheat on her boyfriend with me. To be honest, my mentality has always been once a cheater also a cheater, but still I pursued. Til this day I kick myself for letting us do that to her now ex. Later on in the relationship, she confesses to me that was not her first time cheating on that guy.

We haven't had the greatest relationship, but its one we are working on.

Recently she told me a story about an friend of a long time confessed he had feelings for her, and the thought that they should be together has crossed through his mind. When she told me this story I asked her what her response was. She told me " I told him I have a boyfriend and he has a girlfriend. And I've never really thought about him that way."

I hate myself for doing this, but I became white trash the next day. I looked through her Facebook to see if she was lying or not. (TRUST ISSUES HELLO! but can you blame me? Red flag has been up since the beginning.) Of course she was lying to me. She told me she has had those thoughts as well. She didn't pursue the matter, but she did re-affirm it. She then went on to tell this guy about our relationship problems. She divulged some personal information about me, and most of it was half-wrong and inaccurate.

I know she lied to me and I don't know how to bring it up? I'm worried she will leave me for him, like she did to her ex. What do I do?

Can you condense the text into a few key points?
<bot>: Girlfriend is lying. She has cheated before. Read her facebook (because I'm white trash) And saw a conversation of what the beginning of our relationship looked like when she had a boyfriend, with another dude.