Question Summary:
Does having intimate relations with one’s mother in law make one’s wife unlawful?

Question Detail:

A person has been married since 16 years and has three daughters and a son. One or two years before marriage, his mother in law was intimating him after that they (he and his mother in law) had sexual contact but not intercourse (Dukhūl). After the marriage, they did not have that type of relation.
He heard from some source that her daughter was Haraam for him, so his marriage is not valid with her daughter. In that case, children are also not Halaal with him and his wife. He loves his family very much. At the time of marriage, he did not know her daughter will be Haraam for this action. He is very ashamed for his action since that time till now, and asked forgiveness from Allah. Now he is very much worried about his wife and children. His wife did not know about that.  It will be very difficult for my daughters and son to survive with separated parents. My question is, his marriage is valid or not? 

Answer :

 
In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.


In principle, it is necessary to follow one Madhab. If the man in reference is a follower of the Hanafī School, then the implications of Hurmah al-Musāharah will apply in such a situation. In other words, due to having intimate relations with one’s mother in law (despite the intimacy occurring before the marriage), his wife is unlawful upon him.[1] It is necessary for him to terminate the Nikāh with his wife by making a verbal declaration such as, “I have terminated the institution of marriage between us”.[2] Nevertheless, in such a case the lineage of his children is established with him and they are considered to be rightful children of the married couple.[3] 
If he is a follower of the Shāfī School, then the implications of Hurmah al-Musāharah will not apply. In other words, it is permissible for him to continue with the marriage.[4]
Note that it is not permissible to switch Madhabs (schools) for purposes of convenience.
And Allah Ta’āla Knows Best
Abdul Azīm bin Abdur Rahman,
Student Darul Iftaa
U.S.A.
Checked and Approved by,
Mufti Ebrahim Desai.