Is the wife considered sinful if she refuses to engage in sexual relations with her husband who has another wife?

It is not permissible for a woman to refuse her husband's request for intimacy unless there is a legitimate excuse, such as illness, menstruation, obligatory fasting, or harm. A severe warning has been issued for a wife who refuses without a valid excuse. On the authority of Abu Hurairah, may Allah be pleased with him, the Prophet, peace and blessings be upon him, said: "If a man calls his wife to his bed and she refuses to come, the angels curse her until morning." Therefore, it is not permissible to refuse obedience to the husband regarding intimacy merely because he has another wife.