A poopy doo is when you are engaging in a 69 position with your girlfriend and she farts. Causing you hair to blow back like you stuck your head out of a moving car.
Hey man i was doing the 69 with my girlfriend and she farted so hard my hair blew back, giving me a poopy doo.
Also known as a sneek-a-toke, a poofy doo is a cardboard toilet paper roll that has dryer sheets tied to the end of it. Poofy doo was invented by teenagers to be able to smoke weed in their parent's house without them finding out. (doesn't always work) You just blow smoke through poofy-doo and it smells laundry fresh!