ANSWER:

You must continue to remind him that it is his obligation to contact them and to be dutiful towards them even if they were calling him to associate others with Allah. He has no excuse none whatsoever for severing his kinship and he will be admitted to hell for doing that. 

You on the other hand are not obliged to call them or to meet them ever.  

My inlaws have slandered me, done black magic to seprate us (caught red handed by their own son), wanted him to remarry and leave me pregnant and more. I cant forgive them and dont want contact. My husband cut ties with them and hates them after seeing my suffering and their double standards and unislamic values. I tried asking him and reminding him of his parents rights, what else can I do?

Fiqh of the family |