Can his actions split us apart??

Ok i just got married about 2 months ago and moved back in with my parents. Now me and my husband have a newborna and he has a child before me and having problems with his baby mother to the point where he wants to get custody of her. The problem is if he gets custody of her my parents mgiht not approve of him bringing ehr to live with us and not only that my room can hardly accomidate us plus my baby. I had my own apartment where he brought her over every now and then. So he came up with the solution if he gets custody of his daughter to move back in with his grandma and bring his daughter and I feel that will split us up. I dont like that idea at all. I dont understand why he is taking it that far. I feel if she is going to take him to child support that he should just let it be because if she dont do it now she will do it when his daughter is like 17 years old and get him for all that money. The next thing he is thinking is giving up his parental rights and when she gets older then they can have a relationship because he dont wnat nothing to do with his baby mother. What should be done in this situation adn what should I do? I feel in the middle.