Favor from a Wealthy Family: Where Can My Wife Run Away?

A stranger invited me to a high-end restaurant for dinner and said that his father and my father were close friends, but I had no impression. I was eating, and the person working in their family called me "young mistress" for no reason, even in front of the elders. The strange man agrees with everyone's title and regards me as his wife, but I have only known him for a few days...