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

Im mostly looking for advice on what to say to her... I can't really provide that much info on their relationship, all i really know is that it wasn't really that good for the last month and she was accusing him for cheating.. Im guessing she did it for revenge..

It all happened when we were out drinking with a few friends on our local bar. We were all having a good time talking and joking with each other, except her.. When she was talking with someone it was with the other girls in the group and pretty much all of a sudden she sent me a message and told me to come to her apartment (about 250m from the bar).. I was guessing she wanted to talk with me in private since we had know each other for the longest..

When we got to the apartment she told me that she was not feeling to great and didn't really want to stay at the bar.. We talked for a bit and when i was about to leave she asked me to stay, which was fine by me since i live 10km from the place and would save me the effort to get a cab. 

We went to bed and she wanted to cuddle and i asked her about her boyfriend situation. She told me that they had broken up earlier and she just felt that she wanted to be with someone. Things get more intense and after the act when we are cuddling she starts to cry and tells me that she is now feeling shitty about what we did..

The story pretty much ends there, it has been 2 days since then and I'm kinda feeling shitty about it as well... we haven't really talked about it with each other yet, and I don't really want to ruin our friendship because of this...
<bot>: Female friend broke up with her boyfriend, had (what I assume was)revenge sex with me, she is now feeling shitty about it, and i don't know what to say to her...