Does a relative's saying to his female relative, "You are my wife," and her joking reply, "You are my husband," in the presence of her family and guardian, constitute a marriage?

A man's saying to a woman who is not his wife, "You are my wife," and her saying to him, "You are my husband," does not constitute a marriage, whether they are serious or joking. This statement is objectionable, false, a lie, and an impudence that is impermissible between non-mahrams. Marriage is only valid with specific conditions and pillars, including the guardian (wali), witnesses, and offer (ijab) and acceptance (qabul).