When you sprinkle pubes over your partners anus after cum comes pouring out.

When you crumble a booger (boogoo) onto the person sitting next to you.

1.) an idiot;2.) someone you don't like, a slang word you a garbage person.

Simply, its where one places an apple pie (Favorably, the Kipling variety is used) over the receiving chaps anus, and begins anal intercourse with the said arsehole essentially crumbling up the apple pie over the rectal passage. The end resulting jizzy pooey apple crumble is then shared, A delacasy in certain parts of the world.

The act is not strictly kept to the gay community however, no known documentation of women trying Bert's Apple Crumble have been found.