What is the ruling on a man secretly marrying a woman, with her consent, and with two Muslim witnesses, when the reason for the secret marriage is their differing nationalities, and because she is a widow with children whom she fears being deprived of if she marries publicly, and given that the husband is aware of her circumstances and cares for her orphans?

If the marriage fulfills its pillars and conditions, namely a guardian, a dowry, and witnesses, then it is valid and is not harmed by concealment, according to the majority of scholars. With the mother's marriage, her right to custody of the children is forfeited, based on the Prophet's (PBUH) saying: "You have a greater right to him as long as you do not marry." This right then transfers to someone else. It is not permissible to use deceit to nullify someone else's right, and merely having witnesses for the marriage without the presence or consent of the guardian is not sufficient.