doing something ass-backwards (literally, in it's original form)
This term sprang
like a phoenix rising from the ashes from an incident that happened to a friend of mine. We'll call him Dude. Dude had the flu, and everything that comes with it, and was sprinting toward the bathroom for the millionth
time with diarrhea when he realized he had his underwear on backwards. With no
time to spare he proceeded to "do his business" through the
fly opening or, to poop of out of the peehole.
As the phrase rolls off of the toungue so easily, it came to have many different applications.
*Parts of this
story may have been dramatized for effect