Stepfather Mahram after divorcing mother
18-10-2016 | IslamWeb
Question:
Assalaamu alaykum. Are your parent's previous parents still treated as Mahrams (permanently unmarriageable) if they are no longer married to them but have divorced? So if you ever see them anywhere, can you look and talk to them like with an uncle or father? Is the stepgrandfather and stepuncle a Mahram too after your parent has divorced? If so, is it an obligation to keep in touch with them and their family? For example, when you hear that one of them is sick and that others are elderly and unwell? They were previously stepfamily for some time and are distant relatives with us too. May Allaah reward you.
Answer:
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 
is His slave and Messenger.
The stepfather is a Mahram (permanently unmarriageable) even after he divorces her, as long as he consummated the marriage with her. So it is permissible to look at him and talk to him like with other Mahram men. However, if he divorced her before consummating the marriage with her, then he is a non-Mahram. Allaah says (what means): {…and your step-daughters under your guardianship [born] of your wives unto whom you have gone in. But if you have not gone in unto them, there is no sin upon you.} [Quran 4:23]
The step-grandfather is like the stepfather. But the step-uncle is not a Mahram. Please refer to fatwa 312058.
Finally, you should know that the relatives that you are obliged to keep ties with are the relatives by family lineage, such as the brothers, sisters, maternal uncles and aunts, and paternal uncles and aunts. As regards the in-laws or relatives due to breastfeeding, such as the stepfather or stepmother, then it is not an obligation to keep ties with them in the same manner as the relatives by family lineage, but it is desirable.
For more benefit, please refer to fatwa 197695.
Allaah knows best.