Impermissibility of playing with the sister-in-law

Q 4: Is it permissible to play with the grandfather and wife of the older brother?

A: It is not permissible for a man to play with his brother's wife, because he is a non-Mahram (marriageable relative) to her. He is not even allowed to shake hands or be in a state of Khulwah (being alone with a member of the opposite sex) with her. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.