WIVES, as opposed to mistresses, have been granted special privileges in Islam:
Futile talk is not allowed after Esha. But the Holy Prophet (sallallahu alaihi wa sallam) is reported to have told his noble wives stories after Esha.
FROM A HADITH we learn that looking at one’s wife strengthens the eyesight. (Kanzul Ummaal, Vol. 16, P 273). When the spouses gaze at each other with love, Allah Ta’ala favours them with a Gaze of mercy. (Kanzul Ummal, Vol. 16, P 276)
Serenity in marriage lived according to Islam can never be found in adultery