Firstly, thanks for the contributions, I didn't expect so much feedback!
I'll try and answer some questions and give you a bit more insight.
He's 28 and I'm 24. We've been together for a year and a half, on and off. We've had difficulties, much greater than this one and I still believe we should be together. We are a very unlikely couple and it's our differences that allow us to benefit from each other. We keep each other in check and give each other a different perspective on things, we make each other rethink our opinions and even values and keep each other growing. We keep challenging each other and have evolved as individuals ever since we met. This is why I would like you to please not advise me to simply break up because there's more to the story and our social preferences are not greater than the rest of it.
And yes, he wants to act like a frat boy, and I strongly believe he should. He never got to do that before, growing up in Muslim countries, and now he can and he should. He's not planning on being a frat boy his whole life and I certainly prefer him being one now rather than later when he's attached to higher responsibilities.
He and I met in a shared flat and started off as roommates. He moved out a few months ago and it benefited our relationship since we need more space for ourselves before we move forward. We still see each other almost daily, so he gives me a lot of attention and is very caring in that respect.
He moved into a new shared flat and this is where he met the friends group I'm talking about. They're mostly female. As roommates, they also spend a lot of time together. The walks and movies happen spontaneously, so I don't get invited to these but to more organised events like parties.
I don't refuse to join them every time I'm invited. I've made an effort, especially at the beginning, but I just wasn't comfortable. I said I'm not a party person, but that was a short explanation. In reality, I am, and also very social, but I am not quick to trust people. These people are still strangers to me and I would need to get to know them better to feel comfortable around them when my guard is down. Since this was important to him, I invited them all to a more calm get-together, so I could use the opportunity to get to know them better. They blew me off, without ill intention, since they didn't realize it was an important thing for him and me. I asked him to talk to them and have them put some effort in too, but all he did was tell them I'm uncomfortable with parties and they just accepted that's why I wouldn't be joining. That's when I asked him to keep us separate, to do the things he enjoys with them and stop insisting I be a part of it when I wasn't comfortable with it. We'd both ideally want me to be a part of it all and to feel good about it, but I can't make that happen forcefully.
I'd be fine with this new arrangement if he hadn't started blowing me off when a roommate thing would come up. That's when I felt neglected, not prioritised, and like a second choice. That's why now, even with him prioritizing our plans and time together, I feel triggered by him spending time with them because it brings up the feelings of being neglected and passed over for something else.
