Is a man considered a Mahram for the sister of his wife?

Question:

Is a woman’s husband a Mahram (unmarriageable) to her sister and paternal aunt so he can sit alone with any of them?

Answer:

No, a woman’s husband is not a Mahram (permanently unmarriageable relative) to her sister or paternal aunt. The husband of a woman is a Mahram neither to her sister, nor to her maternal or paternal aunts. It is only that he cannot combine any of them in marriage along with his wife, which means that he is a temporary Mahram to them. Similarly, the husbands of a girl’s sisters or of her maternal or paternal aunts are not Mahrams to her.

On the other hand, neither the paternal aunt nor the sister nor the maternal aunt of the wife of the mentioned husband is a Mahram to him since they are temporarily unmarriageable to him, i.e. once he divorces their sister, the daughter of their brother, or the daughter of their sister, it is permissible for him to marry any of them after ‘Iddah (woman’s prescribed waiting period after divorce or widowhood). It seems that some people are lenient in dealing with some women; some women are lenient in dealing with the husbands of their sisters; and some women are lenient in dealing with the brother of their husband or the paternal uncle of their husband. This is wrong and not permissible. It is not permissible for a woman to be lenient in dealing with her brother-in-law, since he is not a Mahram to her. Likewise, neither his (the husband’s) paternal or maternal uncle is a Mahram to her (the wife). Rather, her Mahrams on his side are his father and son. As for the husband’s brother, paternal uncle, paternal uncle’s son, and maternal uncle; none of them are a Mahram to the wife.

Similarly, neither the husband of a girl’s (woman’s) sister, nor the husband of her paternal or maternal aunt is a Mahram to her. Rather, her Mahrams are the husband of her daughter and the husband of her mother. As for the husband of a woman’s sister and the husband of her paternal or maternal aunt; none of them is a Mahram to her. She should wear Hijab (veil) in front of them and should not sit alone with any of them.