All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
All the children of Aadam commit sins, but the best sinners are those who repent as confirmed in the authentic Sunnah of the Prophet . However, if a person sincerely repents to Allaah, then Allaah will accept his repentance and forgive his sin. Therefore, if your husband regretted the sin that he had committed in the past, then regretting is (a form of) repentance. Nonetheless, he should make this as a true and sincere repentance to Allaah while fulfilling its conditions which we clarified in Fatwa 86527.
If the signs of repentance appear in your husband and he stays steadfast on righteousness, then you should not talk about this matter again and again nor preoccupy yourself with it as this does not bring any benefit; rather, it causes harm. If you preoccupy yourself with this matter, you may become sorrowful and keep the door open for the devil to cause dissension between you and your husband, and so, the family will break up and your children will be the first victims.
Dear sister, you should ponder over the Hadeeth narrated by Jaabir that the Prophet said: "Iblees (the devil) places his throne upon water; he then sends detachments (for creating dissension); the nearest to him in rank are those who are most notorious in creating dissension. One of them comes and says: I did such and such. And he (Iblees) says: You have done nothing. Then one amongst them comes and says: I did not spare so and so until I separated him from his wife (i.e. he caused him to divorce his wife). Then Iblees goes near him and says: 'You have done well.” [Muslim]
On the other hand, by you raising this issue again and again, you may help the devil against your husband who may go back to his old ways (because of your continuous hassle). Abu Hurayrah narrated that a drunken man was brought to the Prophet who said: "Beat him.” Abu Hurayrah said: “So some of us hit him with our hands, and some with their shoes, and some with their garments. When that drunken man was leaving (after they finished beating him), someone said to him: “May Allaah disgrace you!” On that the Prophet said: “Do not say so. Do not help the devil against him.” [Al-Bukhari]
Therefore, we advise you to forget what happened and look to the future and cooperate with your husband in righteousness and piety.
Finally, we advise you to do the two following matters:
1- You should beautify yourself to your husband and speak to him in a soft and gentle manner and take care of him so that he would not think about other women.
2- You should make a (Dawah) programme for your family. This programme should include the remembrance of Allaah, the recitation of the Quran and listening to some sermons so that you would strengthen your ‘Eemaan (faith), and this will be a strong protection for you from committing sins. Indeed, the weakness of faith is a reason for heedlessness and following one’s desires.
Allaah Knows best.