The act of urinating inside of a man or woman's anus shortly after completion of anal sex. It is so named because a #1 is taken on top of a #2 and the resulting mess is extremely smelly and sticky. As this is one of the most horrible things one human being can do to an other it is almost always accompanied with a subsequent break up.

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.