Should the first wife seek a divorce to spare the second wife from divorce, taking into account that the second wife refuses to be fair between the two wives and threatens divorce, and what should the husband do to be fair between his two wives without wronging either party?

A husband's lie to his second wife, telling her that the first wife is "only on paper," is an unlawful act. It is considered a valid condition that permits the second wife to seek annulment. It is forbidden for a man to practice polygyny if he knows he is unable to be just between his wives, and if he fails to be just between them, he is sinful. It is forbidden for a woman to seek divorce unless there is a valid reason, such as harm, mistreatment, or injustice. It is not permissible for a woman to ask her husband to divorce his other wife. The one who is harmed should demand her right, and patience is better. If a divorce occurs and the children are harmed, the sin is upon the father.