A child doesn't usually make those decisions
My experience has been that children do not get to say where they live. In fact, in my opinion, it is unfair and damaging to the child to put him in the position of choosing. Your GF needs to file for divorce, ask for custody, and see what the court says from there. She may find that she asks for full custody, no visitation, reasonable support, the ex doesn't respond, the order is entered and she can be rid of him. If he responds, it will be up to the judge to make the final decision as to the level of involvement for the child's father. You and the child's mother are not married so you have no legal standing in this at all. If you choose to foot the bill for her legal fees that's your choice, however, the court will make decisions based on the best interest of the child.
PARENTS are supposed to take care of children not let children make ADULT decisions.
My experience has been that children do not get to say where they live. In fact, in my opinion, it is unfair and damaging to the child to put him in the position of choosing. Your GF needs to file for divorce, ask for custody, and see what the court says from there. She may find that she asks for full custody, no visitation, reasonable support, the ex doesn't respond, the order is entered and she can be rid of him. If he responds, it will be up to the judge to make the final decision as to the level of involvement for the child's father. You and the child's mother are not married so you have no legal standing in this at all. If you choose to foot the bill for her legal fees that's your choice, however, the court will make decisions based on the best interest of the child.
PARENTS are supposed to take care of children not let children make ADULT decisions.