When taking a shit, having someone sit on your lap aiming their anus between the first person's legs. Both people shit at the same time, creating a "double" effect and saving water in the process. For utmost efficiency, time the splashes similar to Olympic synchronized diving.
She sat on my lap while I was on the toilet so we could double decker that shit.
โดย iAM 14 ธันวาคม 2013
U do this to a girl u hate when ur about to climax shove her over and the jizz in ur hand and when she tries to get up shove the jizz in her nose and run away it is called this because u humiliate her twice
Dude I double deckered that bitch yesterday
โดย Hoddy toddy 19 มิถุนายน 2014