<human>: Condense the text into a few key points

Me and my Gf have been through a lot. Last night at the bar were drinking her co worker  happen to be at t at the bar. Him and her were getting along a little to well so I cracked what I through was a funny joke on him. My girl took it the wrong way called me racist. and left me with the guy I took off after her. 2 weeks pass everything seems ok. Then She tell me were over and she moving out. Week later I see her with him on face book kissing and now  In a relationship. Like wtf I make one black joke and I'm the bad guy ?  after all we have gone through. I really don't know what to think.
<bot>: when to bar with my girl, make black joke at her coworker she gets pissed, moves out and starts dating him