Bros before SOs

Nowadays, my boyfriend only ever wants to do things with me if his friends come. We'll plan for a Friday night dinner out, to which he will invite his friends. He'll say he'll meet me at my house before an event, and then runs an hour late waiting for the guys to join him. He'll tell me he would like for us to camp over summer break, only to invite all of his bros. I'll suggest to go out or watch a show/movie, but he'll only have the energy to do so if at least one of his buddies come. If I suggest something to do, he'll feign disinterest; but if one of his friends recommends it, suddenly it's interesting. He'll invite me over to stay at his house and ends up just talking with his housemates until we go to bed. Do any of you other ladies have this problem? How do you deal? Is it a serious red flag?