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I have been living in with my girlfriend for over 4 years now. We were going through a rough patch in Jan and didn’t talk much but still lived together, I found out during this time that she has been cheating on me with my best friend, this happened 6-8 months back. I also found some of her msgs with other guys.Upon confronting she denied everything with my best friend and said it never happened and she justified the msgs saying we were not talking for couple of weeks so it’s ok to msgs guys. My best friend told everything in detail about what happened between them and I don’t know who to believe. She begged me come back to normal again, it’s been a month now since this incident,but I am not comfortable. I do still live with her.. now we are on a break and I find her chatting all the time to guys her justification again is we are on a break. What do I do? How do I handle this situation.

Tl;dr: Gf cheated with my best friend now we are on a break but still living together, she is going on dates with guys. What do I do ?