I know the em has a great community and some of you know me and others won't, since I play really little now but I need some honest advice from a neutral third party. Please!

Ok honest opinion please: seriously.

How would you interpret the situation:

Facts: My girlfriend's ex invited her, among 3-4 other people to an event. She messages him and declined the offer. They then message back and forth briefly for a few days essentially catching up as friends do - nothing weird in that regard. He does sound a little flirty, reflecting on their past and little inside jokes they had. She doesn't really respond to it but "replies back to the banter." They chat about me for a while, just saying how "good luck to [me] trying to deal with [her] mood swings (etc)." He then asks to call for "15 minutes" to talk about some stuff to do with church groups. They end up talking for an hour and from what I was told it was like a "catch-up" as they talked about things like me, university, their careers and their friends now and "that was about it." Also, we were at a bar last week and he was there too, he comes up randomly and hugs her, shakes my hand and leaves. She was flustered and didn't hug back (no issues with this). In the messages, he says that he "really needed that (seeing her for a moment)" because he has been having anxiety for the last 6 months. They broke up over a year ago.. so yeh. We've been together less than 6 months.

So that's all that happened.

She tells me that she had 0 intentions about anything bad and that it was just a catch-up because "eventually she will want to be friends with him again because if we're all adults, we can all move on and be mature about it."

She apologised and admitted that she shouldn't have done it in hindsight, but based on the fact that we should all be mature about it and since she wants to be friends, she can't see him "as an ex" forever. Therefore, she says that she doesn't think what she did was wrong, especially when she said that that's how she would talk to all her friends. She also mentioned that it was supposed to be like "from one youth coordinator (church) to another" so it was professional, but the 1 hour call at like 11pm seems a lot more social to me since nothing about the church was apparently discussed.

Do i deserve to be annoyed?? It's so petty of me to be like "you can never do this again" because logistically there's nothing wrong with being impartial friends again.

How would you interpret the situation and react?

I feel that it's a different scenario when it's an ex, it just is. I said if the situation was reversed, how it would've went and she agreed she wouldn't have liked it if it was my ex, but she saw not much wrong with the chat for 3 days and eventual call.

This is a lot better than being cheated on or having to pick her up from the ex's place or anything (which happened to my ex, in comparison). But anyway, what should my have been?!!? And what should she have done in her situation?? I thought it would've been politely decline the event, maybe send a message. Not reply and "banter" (flirt in my eyes...) back for a few days and then catch up and chat on the phone for an hour.

The worst thing is her friend asked her not to tell me. So that friend I feel they've been anti-railing me anyway. Oh also, sure, the ex might be to blame and out of line to message like that or call or flirt and stuff, but what he does with his life can't be my concern and it always takes two to tango. I want to know if what my girlfriend did is acceptable, am I being unreasonable, what you would respond to the situation as well.

Thanks in advance :( Idk what to feel or respond. She openly showed me all the messages and she told me what happened but during which she decided to message and call she had no intention of telling me.

Anyway, please, thoughts?