During the act of anal intercourse, the person on the receiving end has a nasty case of firerreah.

The outcome is something to the effect of putting your thumb over a garden hose.

Dude, last night a brownie earthquake went down in my house and it shot about 3 yards in each direction.
by alejandro hayes August 29, 2007
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Poop Terminology: a poop that is watery, brown, and stings. The after effect is mild to severe itching.
When John finished in the bathroom, he knew he had made a brownie earthquake because his butt was stinging.
by poop terminology lord May 22, 2008
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