Is the husband considered sinful after deflowering his wife, with whom he has a marriage contract but has not yet consummated the marriage? And is it permissible for him to divorce her after discovering her association with a man of ill repute, taking into account the Hadith about the Dayyuth (cuckold)?

The first point: There is no harm for the husband in going against custom with the wife's consent after the marriage contract, as she has become his lawful spouse.

The second point: The husband should not hasten to divorce based merely on suspicion. Rather, he should advise his wife and remind her of God, so she avoids situations of doubt. If she persists after that, or if she is unchaste, there is no good in keeping her. In this case, divorce is recommended, as Ibn Qudamah mentioned. If she repents and becomes upright, then there is no effeminacy in keeping her. Divorce is the husband's right, before and after consummation, provided he fulfills her rights. And whoever fears God, He will make for him a way out.