Fatwa ID: 05610
Answered by: Mufti Javed ibn Nazir Kachhalia
When my friend was about 14 or 15 years old he used to sleep with his mother one day devil attacked him and he began to masturbate and even touched his mother’s body with lust thinking in mind that she is some another woman but in reality, he knew she is his mother
Now he is 20 years old and his life has changed now because of Tablighi Jamaat and he has repented from that sin but he got to know about the law of hurmat musahara that as a Hanafi his father has to divorce his mother he is very very depressed as this will destroy his family
In the name of Allah, the Most Gracious, the Most Merciful
In regards to the aforementioned case;
It is written in ‘Fatawa Mahmoodiyyah’:
“To touch the mother with lust even by mistake it will be considered as ‘Hurmat Musahara”.
Further, it has been mentioned in ‘Fatawa Darul Uloom Deoband’:
“The primary ruling is by touching with lust” (Extracted from Ad-Durrul Mukhtar). 
Only Allah knows best.
Written by Mufti Javed ibn Nazir Kachhalia
Checked and approved by Mufti MohammedTosir Miah
Darul Ifta Birmingham
 Fatawa Mahmoodiyaah Vol 11, Pg 406, Jamiah Farooqiyah
 Fatawa Darul Uloom Deoband Vol 7, Pg 256, Darul Ishaat