<human>: Can you condense the text into a few key points?

My Girlfriend and I recently got back together after being broken up for about a month. We had an agreement when we first started going out that if the other liked someone else, they would tell the other. We just had a conversation about whether we flirted or were trying to go out with anyone before we got back together. She tells me that she doesn't want to cause a problem or anything, which leads me to ask her again. She tells me that for the last few weeks, she had been flirting with a guy we both know. While we were still together, they had been alone several times (she said it wasn't a date). She actually recently hung out with him and a couple other friends yesterday. Now normally, I would just move on, but there are extenuating circumstances.

While we were broken up (I was the main cause of the breakup) we agreed to still talk and try to maybe re-evaluate "us". I told her time and time again how sorry I was for being depressed all the time and never being happy, and how much of a piece of shit I felt like that I had made her feel so bad. And she just let me believe that I was the only one to do any wrong.

The guy she was flirting with, we had hung out with, and I noticed they seemed to maybe be flirting with each other, so I asked her if I had anything to worry about. She said no. She ended up telling me that my being jealous of them hanging out was a reason we broke up.
<bot>: We're back together, she broke up with me partly because of jealousy, turns out she was flirting with a guy while we were going out.