How should a husband deal with his wife after discovering her conversations with another man before their marriage, given that he feels distressed by this discovery?

If the wife has repented from a previous relationship, then you must treat her kindly and cover her fault, for repentance erases what came before it. However, if the relationship continues, confront her and ask for her sincere repentance. If she repents a true repentance, then keep her and forgive her. But if her repentance is not evident and suspicion arises from her, then it is better to separate from her after exhausting all means of reconciliation. Spying is forbidden except in specific circumstances. A man must be the maintainer of his wife and have a good opinion of her. Beware of being discontent with divine decree; for everything that happens is by the decree of Allah the Almighty, by His wisdom and mercy.