<human>: Can you summarize the given text in a few sentences?

I've been dating this girl for about 5 months (exclusively) and we've been long distance for the past few weeks on account of her job. She recently told me that she got really drunk while hanging out with friends and shared a bed with another guy (there were beds to spare). He apparently also bit her on the shoulder (twice) which suggests they either made out or cuddled in bed and he decided that would be funny or something. 

Given the situation, what I know about her, and what she told me, I don't think she did anything sexual with the other guy, but I do still believe it was a breach of what we considered an exclusive relationship (she agrees she screwed up).

Our relationship isn't an extremely serious one (ie. I expected it to last the month, but not until winter break), so I've been wondering if I should break it off with her sooner than later to reduce the pain of a breakup even before this incident.

At this point, I probably will break up with her. However, I'd like advice for how to do it. This has been a really enjoyable relationship, and i think she's an awesome person, so I don't want her to think she's a terrible person when I do break up with her. Fortunately, I do think she's in a good place in her life, so this may not hit too hard. Any advice on how to break up with her while minimizing how much it hurts her?
<bot>: gf slept with other dude (no sex) and I've been thinking about breaking up with her anyway. Want advice on how to minimize the harm, but still break up