if one is to commit a flap doodle, they would be flap doodling. Flap doodling is to participate in an act that your parents would not aprove of. i.e. sex, drugs, alcohol, wacking off etc.
"I will let you have your flap doodle now... but next time, let me be clear, there will be no flap doodling on my flap doodle time!"
by I.LOVE.WAFFLES. June 7, 2009

by Sage McAilister July 26, 2003

by Franco Vivaldi November 16, 2005

by Andy K March 28, 2004

similar to mud flaps on a truck-butt flaps are a new fashion accessory. They come in plain, name brand, and chrome (popular with the ladies). Can be used to keep the dirt from kicking up while you're running or simpley to just say "Hey, look at my butt flaps!" Hopefully, one day, the famous rapper Little John will come out with his own line of butt flaps.
by Silly Sanfilippo December 23, 2005

by staniel clifford April 20, 2009

Your lips.
by ilikedinosaursrawr November 7, 2010
