<human>: My girlfriend and I have been together for about 2 years now and I love her, but we can't agree on this and I need some advice. I've asked my friends and family but of course they took my side so I need an outside opinion.She still hangs out with her ex boyfriend alone even though she knows I'm not okay with it. She says that they're good friends and they want to see each other once in a while. 

I have ex girlfriends that I don't hangout with anymore because I know it might end up causing conflict. I know that exes can be friends but usually there's still some feelings left there. I just can't shake the feeling that her hanging out with an ex while she's in a serious relationship is a little weird. I guess I need to know if I'm overreacting and being too protective of her, or if this is something that she needs to stop.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: Girlfriend of 2 years still hangs out with her ex (alone) even though I'm not comfortable with it. Am I just overreacting?