Ex-boyfriend is flirting with my friend Options

[Little Bird]

Hey,

Last year I had this boyfriend who I couldn't stand by the end of the relationship (despite that I told him I would still be his friend). He was upset over our break up over the summer and I could tell that at the beginning of the year he still liked me a little.

Now I always see him flirting with my friend who likes him at play practice. When I first noticed that it made me really angry. I didn't understand it. I don't love the guy and going out with him was the worst choice I ever made so why is this making me so angry? I also feel like there is something I have to win but I don't know what it is. I've come up with a few solutions.

1: Maybe I still have this idea that he belongs to me or something because when I see them flirting it feels so surreal.

2: I feel like I've been winning since June (the break-up). Since I haven't really liked him at all since our relationship ended I feel like I had power over someone I don't like and that is satisfying. However, if he is over me for sure, I've lost. But I don't kbnow what I'm trying to win.

3: He might be trying to get back at me for the break-up by flirting with my friend (and soon going out with her).

Maybe it is one of these, or maybe it's all of them. I don't know exactly what it is yet so if someone could please give me some more ideas that mght be nice.

I really want to know who else has ever felt this way before. I want to take the high road and let my friend go out with him but I don't know how to get over this anger. Do you guys think I'm being a total brat over nothing or is this natural? I've never had a boyfriend go out with my friend before.