What should a wife do when she discovers her husband's infidelity and his continuous change, along with his ongoing communication with another married woman?

A husband engaging in a relationship with a foreign woman who is married is a great evil (munkar), an act of disobedience to Allah, and a betrayal of his wife. We advise patience and supplicating for his guidance and repentance. Otherwise, the wife has the right to seek divorce due to his transgression (fisq). If the husband is spying, that is an evil (munkar) from which he must repent. In case of fear of magic (sihr), legal ruqyah (exorcism) is recommended. The husband is legally obliged to treat his wife kindly, as this fosters harmony, affection, and family stability.