I have been with my gf for about two years. A while back towards the beginning of our relationship she invited me to some after work gathering at a pub. I shot the breeze with some people there trying to just be friendly with strangers. One of those people was her proclaimed work-bffl a (~25 M) and his girlfriend. I had a few exchanges with them about coffee roasting and his gfs career, everything seemed like a friendly/ cordial exchange. Well as it turns out, my gf tried to set up double dates with them and apparently he diverted/ deflected the invitations with me until eventually confessing he’s “not a fan of me” and thought I was rude to his gf and self-centered (allegedly). This is out of left field for me as I don’t recall anything close to an interaction that would’ve warranted that response but I’ll take it for what it’s worth, everyone’s entitled to their opinions.

Well, this situation with her coworker and his dismay for me was kept as a secret for basically a year. Within that time span, she’s had a meetup with him and his gf where she framed it as meeting up with them while blatantly omitting an invitation to me but I brushed it off not questioning it as I didn’t want to seem petty and didn’t expect any foul play. Fast forward to a few days ago she mentions in passing that he sent her a bday invitation for Saturday. Again, just a strange omission of mentioning it as an invitation to both of us but I still don’t question it, assuming maybe there’s a miscommunication with her phrasing. So, the day of the party comes and she doubles down saying hey so I’m stopping by his party this evening… at this point I just ask straightforwardly; “so are you just not inviting me to come with you? Tf is up with that?” Mind you I’ve invited her to basically every one of my family or friends invitations. She deflects and redirects the conversation into an argument about how I didn’t make plans with her yet and how I didn’t see her the night before and so on.. basically diverting away from the simple question at hand. After pressing her again she finally spills the beans saying “yeah he’s not a fan of you” and gives me the alleged back story. I was dumbfounded learning that he was sending her invitations while explicitly requesting to not have me involved, feeling like this guy at her work is basically trying to ostracize me from my own gf. That’s not really my problem though, the main issue to me is that she catered to this coworker’s request and went to his party and their previous meetup as I’ve just learned solo. Pretty much ditching me on a Saturday night for a male coworkers bday party who’s explicitly requested me not to come.

I don’t believe a loving partner in a relationship would do that. I know I wouldn’t, if an opposite-sexed coworker spoke ill of my gf and requested to hang out with just me I’d think that was unacceptable and say hey maybe there’s a way we can all break bread or at least I’d decline her invitations if it meant ditching my gf for it. So anyways, I told her I think we have different value systems and ideas on how a relationship should be and that it wasn’t going to work for me anymore. She didn’t really seem to care as she just texted back that my reaction was disproportionate and basically gaslit me saying that I’m “unhinged” despite feeling like she betrayed me. So now I need to ask Reddit AITHA?