Boyfriends brother and girlfriend

Boyfriends brother, brothers girlfriend and step kid want to move states and he pretty much told them they can stay with us i have never met the girl or her kid and i have kids and step kids who come over every 2 weeks He didn't even check up with me first to make sure it's ok they're coming to "check tx out" but I don't want them sleeping in our home I don't feel comfortable doing that he's upset that im mad about it and said no but to me that's just weird