Advice?

So I'm looking for a place to live for me and my son. My bf offered for me to move in with him as long as his mom and sister who he helps with rent are ok with it. But I told him ok, what about my son, cause we are a packaged deal. And he was like idk if they will be ok with that and I said then no I don't go anywhere without my son. I told him we need our own place as we are expecting a baby due in October, am I wrong?