You shouldn't misbehave or you'll be punished by your teacher.
Fred is sitting with friends at a school assembly and is bored by the presentation.
Fred wants to talk with his friends.
Fred takes out some paper and a pencil and passes notes to his friends.
Fred starts talking with his friend, laughing and joking.
Fred and his friends carry on a silent conversation unnoticed.
The supervising teacher sees Fred and his friends and gives them all after-school detention.