What is the ruling on a repentant woman marrying a man with whom she committed a sin, after her imprisoned husband has divorced her, and does this marriage expiate the sin of fornication?

If the husband is a drug addict and commits adultery with foreign women, the wife should seek separation from him. Establishing an adulterous relationship with a foreign man is one of the most heinous acts, a neglect of Allah's right, and a failure in the husband's right. Adultery often begins with leniency in its preliminaries, and Allah Almighty has warned against following the footsteps of Satan, which lead to immorality and evil. Sincere repentance is obligatory, and its completion is to separate from the foreign man and cut off any relationship with him outside the framework of marriage. It is permissible to marry this man if they both repent to Allah and the waiting period (iddah) after the khul' has expired. The iddah of a woman who seeks khul' is like that of a divorced woman, and according to some scholars, one menstrual cycle is sufficient.