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

Hi everyone.

I'd like to hear your advice since you seem to be nice people. 

* I [22f] dated a guy [22] for 5 months. He was extremely important to me, as he was my first boyfriend and I was in love with him. We broke up mutually almost 6 months ago. I still have feelings for him.

* The reason for the break up was his lack of commitment and feelings for me, which were clear in the way he treated me. Needless to say, it hurt and still hurts quite a bit. After we broke up, he told me **he still thought about his ex-gf (who he had been with for 7 months) every day. Which of course equals: "I still like (love?) my ex".**

* Here's the thing: when we started dating **they had broken up 1 year ago**. It was very hard for him, she hurt him a lot. Basically **they broke up, but then decided to give it another try, he bought a plane ticket to go to her hometown and at the last minute she told him she was back with *her* ex bf**. Which is just... horrible.

* But... **recently his ex became single again and now they're together again. My ex. With his ex-girlfriend who deeply deeply hurt him**. There are lots of things I'm dealing with, such as having been no more than a temporary replacement, but right now the question that nags me is... 

**Why would he go back to a girl who betrayed him and hurt him so much??** Sure, he never stopped liking her, but how on earth do you go back to someone who did that to you? *I feel like one would have to really ignore his dignity and pride to do that. It seems unhealthy.* 

I know I shouldn't be thinking about this - talk about unhealthy - but I just can't help it. This is tough.. **Any thoughts?
<bot>: my ex-bf went back to his ex-gf, who hurt him a lot. I'm trying to make some sense of it.