What does it mean when my (27F) partner (30M) has stopped inviting me to social events with his friends?

My partner and I live in neighboring cities and see each other at least once a week (usually on the weekend). We’ve been dating a little over 1 year and by now, he’s met most of my friends and I frequently invite him to gatherings with my core friend group, which he has expressed to me that he has fun doing. I have met his friends on less than a handful of occasions and he at least used to invite me to social events on weekends but for the past few months I notice he’s stopped for the most part. He even used to invite me to social events on the weekdays, some of which I did join and we had a lot of fun at. Now, we usually just hang out with just the two of us or occasionally with my friends. I wasn’t sure if I was just imagining it so I asked him recently and he initially denied it and then reluctantly admitted that he stopped trying because he thought I brought negativity.

This was very hurtful because I understand sometimes I tell him I’m not in the mood to go or sometimes when we’re out I express that I dislike him not introducing me or ignoring me when I tell him I’m tired and want to go home, but the majority of the social events we go to have been very positive. He even told me that he had lots of fun, his friends like me, and is thankful that we can do these things together. I am generally an adventurous person and am extraverted and naturally sociable so it’s not like I am awkward or anything with his friends, so I’m not fully understanding his rationale now. I feel that he is projecting his fear of losing his independence and nitpicking on these choice instances as an excuse to justify not wanting to bring me to things anymore.

Overall, I feel very sad (and honestly a little angry that he thinks of me this way). We have been having tiffs lately and this makes me feel like he doesn’t want me included in his social life.

He has also recently been evading telling me about him going out, something that wasn’t a big deal previously and was pretty natural whenever we would catch up. For example, he slips it into the conversation very quickly that he went out to the bar with some friends and then will very quickly change topics and also be vague if I ask how it went. I am mostly confident he would not physically cheat on me, but naturally his behavior gives me pause about him emotionally cheating.

I’ve tried not to be clingy or nosy but seeing a change in his behavior makes me feel isolated and honestly hurt because I don’t know why, especially since he still says he loves me a lot and loves hanging out with me. I wasn’t sure if all this was because he needed space so I offered multiple times for him to have a weekend to himself, but he always insists on meeting up with me and tells me that he misses me.

It makes me feel like I should stop inviting him to social events with my friends but I feel guilty that this would be me “retaliating.” I feel like the more I ask him about it, the more it’ll push him away. I respect that we should have our own interests and friends, but I can’t help feeling hurt by his recent behavior.

Tl;dr Bf has stopped inviting me to or talking openly about social events with his friends, citing that it’s because I’m supposedly a negative person (even though we almost always have fun together and he still insists on seeing me often). What does this mean/what should I do?