What is the meaning of "The Prodigal Son in the Border Town" in the Golden Buddha's novel when I was a child?

It means that Fu Hongxue thought that it was A who had a xx relationship with him, and later he learned that it was B, but at that time he had fallen in love with A ~ The content of Eiweig's novels was similar. The man thought it was cousin A who had a tryst with him, fell in love with each other, and then knew it was another person, but his heart could not be redeemed.