<human>: I broke up with my girlfriend of 6 months two weeks ago, as I wasn't into her or the relationship anymore. My roommate (M 23) and close friend knew her and they talked all the time on fb chat. The night we broke up I had beers with my roommate to cheer up, and the day after he travelled out of town. When he came back, a few days ago, he immediately started hanging out with my ex and now has told me they "had a thing" and are gonna see how things go from here. I feel really not okay about this, and I'm not even sure why. I have lashed out emotionally at both of them, and I don't feel good about having done this. Even if I don't want to be in a relationship with my ex, I have residual emotions about them. My ex didn't take the breakup well at all, and I have been unable to talk to her as she does not want to talk to me - which is fair enough. I am concerned that my roommate is being predatorial on a vulnerable person I care about.

My roommate says our values just don't align, and he thinks that how I'm feeling is territorial and sexist, but he's also being understanding and he thought I was "completely over" the relationship. Is it truly none of my business? Am I wrong to feel hurt? How can I talk about this with my roommate?

Provide a brief overview of the text.
<bot>: Roommate might begin dating ex, all happened very quickly. I'm reacting badly. How should I move forward from here?