Many people in the United States refer to a "number 2" as another way of saying they have to poop. A number 1 is pee, and a number 2 is poop. So we went in public with an oversized number 2 balloon, left it nearby and then asked people if they mind if we take a number 2 right next to them. Everyone assumed that we were about to poop outside right next to them. They were all relieved once they saw the balloon and realized it was just a funny joke.