Is it permissible to prevent a son from marrying a girl with whom he had an illicit relationship, or should he be allowed to marry her despite fearing for him from her, knowing that he is very attached to her? And is it permissible to let him marry her with the intention of divorcing her later, and does this intention of divorce invalidate the marriage contract?

Reckless mixing is forbidden by Islamic law due to the grave corruptions it causes, among which is the natural inclination between the sexes, leading to forbidden relationships. If the forbidden relationship is fornication/adultery (zina), its punishment in Islamic law is lashing or stoning, and marriage between them is prohibited unless they offer sincere repentance. However, if the relationship falls short of fornication/adultery, marriage is permissible after their repentance. Marriage might even be an opportunity for their repentance and uprightness, as the Prophet, peace and blessings be upon him, said: "We have not seen for two who love each other anything like marriage." Furthermore, marriage with the intention of divorce is forbidden and impermissible by Islamic law.