It's bad to soil your pants.
Sam is in the middle of an important math test when he feels the sudden urge to go to the bathroom.
Sam wants to relieve himself.
Sam excuses himself and goes pee in the school bathroom.
Sam pees his pants in the classroom.
Sam is relieved and is able to finish his math test without issue.
Other students notice and laugh at Sam who has to call his mom and go home for a change of clothes.