She knew the relationship would end sooner or later because they just weren't going in the same direction. So I think what happened is a symptom of underlying issues - nothing terrible, but just knowing that they weren't right for each other.Why do you think she did it? Do you think her relationship was having trouble/wasn't a good fit after getting to know each other for a year?
Did her boyfriend find out and he broke up with her, or she took her behavior as a sign that her boyfriend isn't who she should be with, and she ended things?
Her boyfriend broke up with her. She denied doing anything with another guy and told him she slept on my couch, but either he or one of his friends saw us downtown because he described the other guy's shirt. Like I said, nothing overtly WRONG happened in front of me, but I guess he put two and two together.
Her boyfriend also told her she should consider making new friends because it's not cool that I let her "flirt" with another guy knowing she's in a relationship. That stung. But she told him to leave me out of it and that I'm not responsible for anything between them.
I truly had no idea anything bad was going to happen until the elevator doors closed in my face. That's where the naivety comes in and I need to get better about that.