When a group of males go accompany each other to take shits at the same time. This usually occupies all of the stalls in a public bathroom, and occasionally spreads to urinals and, in the extreme, sinks.
Bro 1: Yo man i have to take a dump.
Bro 2: Dude, me too!
Bro 3: Me three!
Bro 1: Yo lets go pull a dump session in the school bathroom!
When in Gears of War 2 you set up an ink grenade in combination with a smoke, so when somebody walks by they are knocked down as they are killed by the ink. Usually requires a combined effort of two people.
" Yo bro go lets go plant that bear trap over by the Boom Shot."