Adultery/fornication with mahrams (relatives) and its atonement
The act of adultery by a man who is mature, sensible, honorable, with a stranger is considered as one of the grave sins which Allah and His prophet forbid. The perpetrators are also threatened by the severe torment in the Hereafter. Allah, the most high, says: And do not approach unlawful sexual intercourse. Indeed, it is ever an immorality and is evil as a way [Quran 17:32].
Moreover, fornicating with a relative is more heinous, most evil of sins attracting grave penalty. It is an atrocious crime that every Muslim must shun, regret perpetrating it, and repent from it – if he ever falls in it- and never return to it again with the hope that he shall be forgiven. It is also crucial that the perpetrator of such sin to constantly engage in acts of worship and obedience to Allah and seek for His Forgiveness. He must always feel remorse and never return to such an abominable act, not even near or think of it.