Would you be okay with this?

If your bf is in a group chat with his female cousins & her friends. They are always trying to link up and go out . Idk these girls I don’t even know that cousin but they are always trying to meet up and do things and I don’t come my bf doesn’t even invite me 😭. One time I saw in my bfs DMS he tried to link one of the girls when he was on a college trip alone and I’m like wtf ? And he was using every excuse saying that’s his cousin ex girl or they use to talk etc which is no excuse or doesn’t make it okay & if I hadn’t seen that msg I would have no idea he went to spend the day with another girl which isn’t okay wit me period because if I was to do that he’d have a fit let alone be in a group chat filled with men.....