-When a cat fucks a dog.
*'Ha! Look at my cat popalopping over there!'
-When you fall down, and your shoe laces come undone.
*'I had a popalop in the driveway this morning.'
-When massive racoons go through your garbage can.
*'Ah man! My trash was majorly popalopped last night!'
-When you forget to shave your under arms.
*'Holy Shit! Did you see christy's grody popalop in gym class today?'

When you eat dirt for the first time and leave your family to build a shack in the woods