<human>: Could you distill the essence of the text into 1-3 sentences?

My girlfriend broke up with me 4 months ago. I was pretty hurt over it but I knew she wasn't as happy as she should be in the relationship with me. Anyway she kept talking to me after the breakup and seemed to want to work back into being in a relationship again. We've been talking almost regularly and even met for coffee and slept together a few times. 

About 2 months ago a bunch of us from my program at school went out for drinks and this girl from my class and I seemed to click at the moment so we ended up going back to her place after and had sex. Just this past month I was with my ex again and she asked if I'd been with anyone else. I denied it at first but she asked again and I confessed. She burst into tears and I honestly felt horrible. I don't think I've seen her as hurt before. I know she hasn't been with any other guys aside from me since the breakup. I still love her and we've been talking about trying to get back together but now I know she's got this distrust in me and I guess I can't blame her. She's more worried about this other girl I slept with than I am because I do see her everyday in class and we are friends. Is there any chance of rebuilding our relationship or is it beyond repair?
<bot>: Ex girlfriend broke up with me but we continued seeing and sleeping with each other. I would like for us to try again but I told her I slept with someone else and now she doesn't trust me. Is it over for good?