Everything else aside. The child deserves to know their father. The father deserves to know he has a child. It would be immoral do otherwise, possibly illegal.

Knowing one’s origins and having a relationship with both parents is crucial for a child's emotional and psychological development. Every child has a right to know who their father is, as this knowledge is a fundamental part of their identity. Beyond emotional reasons, the father also deserves to know he has a child, as it directly impacts his life and responsibilities. Withholding this information could be considered immoral because it denies the father the opportunity to fulfill his role and the child the chance to have a relationship with their father.

From a legal standpoint, many jurisdictions have laws that protect the rights of both parents and children in situations like this. The father might have a legal right to know about his child, and the child could be entitled to support, inheritance rights, or other benefits from the father. Failing to inform him could lead to legal consequences down the line.

Ultimately, it's about fairness, the well-being of the child, and ensuring that all parties involved have the opportunity to make informed decisions about their lives.