I share a two room set with my sister, her baby and her husband. We both share the expenses. He wants to keep his sister's son at home who is a ghair mahram for my sister. he wants him to stay here for 10 days or more in the house of two rooms with a kitchen and lat-bathroom adjacent to the room where the non mahram would be living. the same kitchen and lat bath has to be used by my sister. and the two rooms too are connected. is it permissible or lawful to leave the man at home (my sis alone in the same home working in kitchen)without the presence of any mahram, even for 20 minutes.

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, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

The husband has no right to compel his wife to live with anyone from his family, whether men or women. The wife has a the right for her husband to provide her with a suitable and independent accommodation as underlined in Fatwa 84608.

It should be noted that it is impermissible for the husband to accommodate his wife with a non-Mahram man in a dwelling with shared bathroom facilities, whether she gave her consent to it or refused. Therefore, it is impermissible for you and your sister to accept this situation and you should refuse accepting this man’s stay with you at your house.

You should also not accept his short stay as a guest even for a short time if it entails staying with him in seclusion in the absence of a Mahram.

For more benefit, kindly refer to Fatwa 181041.

Allaah Knows best.