What do you suppose would happen in this situation between a Mother, and a victim of paternity fraud?

The scenario: A woman lies to a man about being the Father of her child...and he raises the child as his own for several years. At some point, she tells him that he's not the Father, but he decides he still wants to be the child's Father.

A short time after, the woman rekindles her affair with the actual biological father of the child, and she tells the man she defrauded that she no longer wants him in the child's life, and going forward, she wants him to leave the child alone.

What do you suppose would happen if the Mother was determined to keep the man who was led to believe that he was the Father...out of the child's life? Whom do you believe the law would side with and why?

BQ: Do you believe the feminists who are criticizing men who are the victims of paternity fraud and decide to walk away for their lack of humanity...would side with the men who wanted to remain in the child's life...or would they side with a Mother's right to keep the man out of the child's life if that's what the Mother wanted?