It's bad to keep secrets from your children.
James sees an invitation for his son in the mail for a birthday party around the same time he has a big test at school.
James wants to make sure his son performs well on the test.
James gives the invitation to his son and says he'll take him to the party as long as he studies enough for the test.
James hides the invitation and tries to make sure his son doesn't find out about the party.
James' son studies hard for the test and is able to go to the party, and he gets a good grade on the test.
James' son hears about the party at school and rebelliously studies very little for the exam.