If ONE of the parents can't be the role model of being a child or children's father or mother, if mother has the best interest and better role of mother, she will get the full custody of the child/children and father will have to follow the court rules, get visitation rights and pay child supports, if not, Mother have the right to stop father to see your child unless he pay the child support. If not paying child support, your child/children can "estranged" from the father which mean your child/children will no longer to see him until the father pay child support.
If the mother can't be the mother role, the father have the best interest, and he will take the full custody, and mother will have to pay child support and get a visitation rights like the court tell you to do. If mother won't do it or can't do it, her child/children will "estranged" from the mom, father have the right to stop you from seeing your child.. I know it is not easy. It is hard to deal with it. If you want to see your child, you can pay child support to the father and he will let you to see Sean. I know it is not fair, it is the court.
If you want a joint custody, which mean, Mother and Father have the best roles and interest for their children and paying equal, and child/children will live with mom for 1 week and dad for 1 week until your child/children make the decision when they get up to 13 or 14 years old due to their schools, involve with community.