Everyone makes mistakes, and there are many reasons for them. Sometimes it's carelessness, sometimes it's giving in to temptation, and sometimes it's deliberate. But no matter what kind of mistake it is, if you know it's wrong and refuse to change, things will never end well.
The story begins with Sha Shi and Xi Meiying having a meal with Sha's mother at a restaurant.
The main reason they invited Sha's mother to dinner was to discuss getting remarried.