Panel 1: The dad is asking how his son's first day back at school was. The kid shocks his dad with an interesting story.
Panel 2: The dad reacts and teaches his son a new bad word on accident.
Panel 1: Dad: Dow was your first day at school?
Boy: Someone got in trouble for saying the "S" word...
Panel 2: Dad: Someone said "shit"?!?
Boy: No, he said "stupid". What is "shit"?
You have to remember the age appropriate swear words.