Fathers Equality Rights

So I have a story about a father and child who are in great need of each other but are being torn apart by a jaded ex. To begin the child is of a very young age and is still very easily molded and shaped, which in my opinion means that he needs both parents to be shaped properly. The father of this child is desperate to have him in his life, but doesn't know where to begin. The short amount of time spent with his father is stained with the disdain put upon him by the jaded ex. The child begins to tell the father that he is going to call him by his first name and that a different man is to be called daddy. (The exes boyfriend) The child also explains to his father that "mommy says I don't have to listen to you... I live at my mommy's house and I don't have to listen to what you say." Now I am going to keep this short because I don't want to get into too many details, but would one be safe to assume that the child in this scenario is being alienated from the father? I may be wrong here, I know that most people assume that the mother should be the one to spend most of the time with her child. But is it not only fair that the father, whom might I add is willing to share custody so as not to keep the child from the mother, should be able to have equal time with the child? I really want to help my friend out in this situation, but I don't know how. I really hope that the american justice system doesn't let us down on this one. 50/50 all the way!