Why do you think you know what is best for your son?

He is a grown man. He willingly entered into a relationship with a woman who already had a child. So, he can make his own decisions and live with the consequences of his decisions, as an adult.

You saying that your son should dump B is not right. Yes, he is not biologically your son's child but he was raised as such. Can you imagine how B might feel to be abandoned by the man he saw as his father figure? Does that not affect you at all?

And of course J deserves a "heathy and mentally happy father" - but so does the child your son raised as *his own*. And frankly, if your son is not doing well it is on *him* as the adult to seek mental health support so that it does not impact the kids, both kids. Getting rid of B will not make your son magically happy.