by MyDefinitionsBeTROLLIN October 22, 2022

The double decker is a combination of the upper decker and a blumpkin. The guy is on the top tank performing an upper decker while the girl faces the wall with her feet on the toilet seat giving him a blumpkin while she drops a deuce in the bottom tank
by tnfungi January 14, 2009

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.
by iAM December 14, 2013

by E.D.M. August 17, 2007

" My boss pissed me off so I snuck into his private bathroom and left him a double decker on his toilet tank."
by Vizualist March 22, 2012

by Urban Dictionary August 24, 2005

The double decker is a strange sex move which consist a woman taking a shit and a guy shoves his cock in her ass without protection while the shit is coming out and then he puts it in the womans vagina and them cums then the woman farts out the cum and drips it on the guys cock then he puts his dick back in her ass while there is still clumps of shit in her then he puts in in her mouth.
by THE_HENTAI_GOD May 19, 2019
