Diez de Mayo

International day where you say "Pee. You may now laugh" and people are legally required to laugh when they hear that saying

*When it's Diez de Mayo (May 10)*
Person 1: Pee. You may now laugh
Person 2: *doesn't laugh*
Person 1: I'm calling legal authorities
Person 2: HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA plz don't sue me