Brother involved with my friendsWatch
Seems like your brother's a people person. I suggest you get used to it but don't let yourself be an outcast, accept the fact that your friends are friends with your brother too and get along with him. I don't know what's the relationship with you two but this is only my suggestion hehe
It sounds like your friends are genuinely friends with your brother too if they're gaming and talking all the time. You should just try to accept that your brother is part of your friendship group too and get along with him too.
You can't own your friends, and it's not even that uncommon to be friends with sibling's friends. My younger sister is in me and my friends' group chat, and my friend's brother is also.