The ruling on shaking hands with the fiancée's mother before the marriage contract

Question:
Another letter arrived from a questioner for the program. He says: One of my brothers from our village proposed to a woman, it was just a proposal, and now he sits with the fiancée's mother and shakes her hand and greets her, claiming that she is his aunt, although the marriage contract has not yet been concluded. What is the ruling on this action? May you be rewarded.

Answer:
This action is not permissible because she is a non-mahram. The fiancée's mother is a non-mahram unless he contracts to marry her daughter. If he contracts to marry her daughter, she becomes one of his mahrams. But before the contract, she remains a non-mahram to him. He must not shake her hand or be alone with her. He must treat her as a non-mahram in every respect. A mere proposal does not permit him to do so. Yes, may Allah reward you with good and bless you.