1 definition by AUXreeeeeee

"The act of urinating in someone's rectal cavity. The actual acronym being slang, meaning "Piss In Your Butt". By many, it is described to be the ultimate sexual feat, sometimes referred to as "fifth base".
The other day I piyb and from then on out, I knew we would have the greatest sex life imaginable.
by AUXreeeeeee June 5, 2007
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