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 (saw) is His slave and Messenger. First of all, we state that Abu Haneefah has the same view as that of the majority of the scholars - that adultery does not establish lineage. However, he was reported to have said: "I do not see any harm for a man who has committed Zina with a woman and she becomes pregnant by him that he marries her while she is pregnant so that he would conceal her sin and the child is his child." As regards someone who has touched his father's wife with lust, Abu Haneefah is of the view that she becomes forbidden for the father. However, the correct opinion is the view of the majority of the scholars that this does not affect the marriage as we have already clarified for you. If a person has committed such a sin, then he should turn back to his Lord in repentance and not inform anybody about it, and the marriage is valid according to the view of the majority of the scholars. If this person follows the Hanafi School, then he may act according to the other opinion as there is more evidence for it. For more benefit, please refer to Fataawa 83626 and 219826.Allaah Knows best. (Source: islam_web) Classified in Women and Family > Marriage Contract