an internet acronym which stands for Pee In Your Butt. This phrase originated on honda-tech.com in the general discussion and debate section. there is much debate as to whether the term was first put into practice by screen name temp or screen name chilly.
During the great honda-tech GDD myspace whore thread of 2006 many people wanted to tell the whore in question "i want to PIYB"
"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.