What is the expiation for one who commits adultery with a married woman?

Adultery is forbidden and an abomination. Its sinfulness increases when committed with a married woman, as it violates the honor of her husband. Adultery has varying degrees of severity: the most heinous is with maharim (unmarriageable kin), and it is more sinful for a previously married person (thayyib), an old person (shaykh), a free person (hurr), and a scholar (alim). The expiation for adultery is sincere repentance, which involves abandoning the sin, regretting it, and resolving never to return to it. For whoever repents, Allah accepts their repentance and transforms their evil deeds into good ones. Whoever falls into adultery should repent and conceal their own sin.