It's a treat. Nobody wants to make fun of it.

Zhang San, Li Si and Wang Wu are three freeloaders. One day, Liu Zhao wanted to play a trick on them and see who paid for the meal. He said to the three of them, "How about I buy some brothers a drink today?" Seeing that they could have a free meal again, the three of them happily agreed. They went to a restaurant, ordered a lot of food and good wine, and several people guessed boxing and ordered food and drink. Halfway through the meal, Liu Zhao said, "You eat first, and I'll go in and see what's good." Without looking up, the three men said, "OK, go, go." Liu Zhao greeted the boss and said, "The three of them will pay the bill later." I left quietly. After Zhang San, Li Si and Wang Wu had eaten their fill, they didn't see Liu Zhao serving and checking out. Only then did they realize that Liu Zhao had been cheated. Who will pay the money? Three people look at me and I look at you. Nobody wants to take money. Finally, Zhang San made a suggestion: "Usually, we all like to eat and drink for free. Everyone says we are shameless. Today, let's compare and see who is the most shameless. The most shameless person does not give money, and the other two give money equally. " Both Li Si and Wang Wu agree. Zhang San said: "I am the most shameless person. I usually come uninvited when I see others eating and drinking. After eating and drinking, I wiped my mouth and left without even saying thank you. Others say that I am the most shameless. " Li Si said, "You are better. I not only eat and drink, but also pack. I don't care if others are sarcastic. They say that I am thicker than the city wall and the most shameless person in the world. " Wang Wu sighed, and Zhang San and Li Si asked, "What are you sighing about?" Wang Wudao said, "You have the face to be shameless. My mouth is facing the sky and my mouth is next to the ground. " Zhang San and Li Si asked, "What do you mean?" Wang Wu said, "I have no face."