So a couple months ago I had an argument with my girlfriend (we've been together for 1.5 years now) about her being too friendly with guys in general and giving off flirty vibes to them without her even being aware, as well as some other stuff regarding the etiquette of being in a relationship and what the limits are. We also talked about ex's and I stated my opinion that hanging out with them isn't something that neither her or me should do.

Fast forward to last night, she was at a party where her ex boyfriend was (she didn't know he'll be there), and I personally don't have a problem with that, but in the middle of the party he asked her and her friend if they wanna go out and smoke a blunt and she, without hesitation, said yes.

The thing about this is it's a pretty harmless situation and I don't think anything wrong happened really, but the way she told me about this was too nonchalant and it didn't even occur that this could potentially hurt me or be an issue even though we talked about situations similar to this.

I thought we were on the same page and had the same values about this kinda stuff, but obviously not and I think it might be painful to continue this relationship as I feel I lost some of my trust for her, and also feel like it just might be the way she is, too friendly and open, and I'm not sure I can accept that.

I'm just too paranoid that his might turn into something worse in the future where I'll just snap and break up anyway... so should I just break up now?