Is the fasting of a wife who is quarreling with her husband and not speaking to him accepted, and is she sinful for denying him his marital rights, knowing that she discovered his sexual relationships with men and teenagers?

It is not permissible to spy on the husband based merely on suspicion, nor is it permissible to abandon him or refuse intimacy unless there is a legitimate Sharia-compliant reason. These messages may indicate a psychological illness, and the solution is not abandonment, but rather helping the husband to overcome this inclination by maintaining prayer and other righteous deeds, for Allah Almighty said: "Recite what has been revealed to you of the Book and establish prayer. Indeed, prayer prohibits immorality and wrongdoing, and the remembrance of Allah is greater. And Allah knows that which you do." [Al-Ankabut: 45]. It is also beneficial for the family to gather for learning and reciting the Quran, and if the husband needs a psychotherapist, he should go to one. Attention should be paid to good companionship between the spouses and fulfilling each party's emotional and sexual needs. As for quarreling with the husband, it does not affect the validity of fasting, and acceptance is in the hands of Allah.