Correct behavior
Personally, I think it is necessary for this mother to test her child by pretending to evade the bill, so that the child can really distinguish what kind of behavior is right and what kind of behavior is wrong.
Independent thinking
Parents' behavior can also make children really learn to think independently, and make children realize that parents, sometimes some behaviors are not necessarily correct. When their parents have some wrong behaviors, as children, they should correct them in time and stick to their principles.
A clever educator
The mother is a very clever woman. She spends a lot of time educating her son. This kind of education is still worth learning and advocating.