<human>: Can you give me a shortened version of the text?

This was a few months back, I believe in November. 

I had been away on business for a week and my girlfriend decided to go out Friday night with a few of her friends. The other friends brought some guys with them. They're bar hopping and wind up at a bar/club around two am. 

Apparently, at the bar/club my girlfriend started flirting pretty heavily with one of the guys. I get back Saturday night and she mentions it to me offhand. Her recollection of the story is as follows:

I was flirting with this guy, no touching/kissing/etc, we danced. My  friend and I jump in the cab, two of the guys get in there with us. We all head back to my apt at the end of the night. I get into bed and fall asleep, he sleeps on the couch. The next day my roommates tell me he was there because he thought he was going to sleep with me. 

My question to her is "What exactly does flirting mean?" and she responds with "I was so drunk I don't remember". This is where my bullshit alarm goes off. I've been super drunk at bars before and I know when I'm giving signals that say hey let's go fuck. 

She says that she didn't give the guy any reason to think he'd sleep with her and that she just flirted a bit. This girl has cheated on her other boyfriends. 

My question to you Reddit: do I believe her when she says nothing happened? Or is this total bullshit and she doesn't want to tell me the truth, that they kissed/made out/sex, etc.
<bot>: Girlfriend goes out with friends, brings a guy home at 5am but doesn't realize that he's there to sleep with her. Doesn't sleep with him (?).