The Rules of Living With the Marauders

When Lily and James bought their house, they posted an ever-changing list of rules on their refrigerator, to be added to as needed. Don't leave chocolate frog wrappers on the floor. Punishment by diaper change is completely legal. Don't hex the shower for any reason (Unless Sirius is singing). Keep obnoxious flirting to a minimum, it upsets Peter. But on one Halloween, the most important rule is broken.