My boyfriend (M21) and I (F21) are part of the same friend group, but he’s been somewhat excluding me from hanging out with them, claiming they're "his friends." Tonight, they’re going out drinking, and he didn’t invite me. His reason is that it feels weird for me to be friends with "his friends,” even though they’re also my friends and I’ve known some of them longer than I’ve known him.
I understand he’s known them a bit longer since I joined the group later, but I was already part of the group before we started dating. I have several friend circles, including this one. However, he insists in keeping our friend groups "separate." He states that it's weird me to be friends with "his friends" and for him to be friends with "my friends." It doesn't quite make sense to me because I quite often invite him to hang out with my friends because he has a good time. Tonight, his friends are bringing their significant others, which adds to my feeling of being excluded, especially since I’ve mentioned to him that I've been meaning to go out drinking this summer.
In short, my boyfriend has always been a little closer with our circle of friends, hence I don't exactly go to all of the functions. I'm a bit upset at the fact that I've been expressing my desire to go out and to catch up with that circle of friends more since I've grown a bit distant with them. There are also our friends' significant others there too which doesn't make it entirely awkward to bring along the girlfriend. I expected him to invite me out since it meets all of my interests, but I'm worried that it may be that he didn't invite me out because he wanted to "separate our friend groups."
I'm quite upset and feeling left out, unsure on how to address this. Any advice on this would be greatly appreciated.