The husband of the wife's paternal aunt as not a Mahram
Is it permissible for the husband of my wife's paternal aunt to shake hands with my wife, being his wife's niece?
Please advise, may Allah benefit you.
It is impermissible for the husband of your wife's paternal aunt to shake hands with your wife or sit in Khulwah (being alone with a member of the opposite sex) with her, as he is not one of her Mahrams (unmarriageable relatives). May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.