Children don't know how to "tease" and "joke".

Show him a humorous joke book with colorful pictures, guide her to read it and watch it with her, so that when you think of the jokes you have seen together in life, it can be said that it is a practical exercise on the one hand and a * * * exercise for both of you on the other. When joking with a child, your expression should be soft or even hippie, so that he can see from his expression that you are joking with her first. Your child is only 7 years old, and the children he comes into contact with are not old. They are not serious about joking with each other, they will see it in their faces. When your child has a preliminary understanding of jokes, he can simply tell that you are telling him some serious jokes. This is to prevent being cheated by others. Let her know that sometimes smirking is not necessarily a joke, but may be deceiving him. When it is serious, it is not necessarily a means of criticizing him or joking.