layin' asphalt
To take an extremely large dump( shit, crap, poop) or whatever you want to call it, particularly one that you are proud of in size or color, and then leave it for an unsuspecting person to find whenever the stall is used again.
"Dude, that was a huge dump you took back there! I can't wait til somebody finds it!"
"I know, I was totally layin' asphalt."
"I know, I was totally layin' asphalt."