Boyfriends best friend blocks me??

It’s super weird because my boyfriends best friend always blocks me from seeing his story whenever they’re hanging out, which is like every weekend & removed me from his instagram on both my accounts (main & spam). He even will confront me about it and say things along the lines of “haha I blocked you from my story”. This has been going on for months and I didn’t think we had anything against each other?? I barely even talk to him. When I ask my boyfriend about it he says he doesn’t know what that’s all about. Anyway, I feel super bad because I just took out my frustration on my boyfriend when I know it’s not his fault. How do I resolve this?