like an upper decker except one shits on the top of the tank lid rather than in the tank

One Bro Gets a blowjob while the girl is on all fours on the ground. While this is happening, another Bro gives it to the girl from behind. Both Bro's preceed to run forwards until the girl is bent in half. Then she makes both Bro's a sandwich.

While taking a duece you realize you need to puke. You cannot reposition yourself so you puke while duecing, therefore you are flowing from both floors, the double decker.

When you take a shit but don't flush and then later take another shit on top of it.

Someone who is really cute and very thick

When one has two pussies stacked one atop the other, for easy alternating insertion. Usually done doggystyle, this position is used mostly in FFM (female-female-male) porn.

When you are jacking off while laying on your bed, quickly stand up on your bed before you're going to nut and aim at the floor.