When a bunch of fraternity guys get together in a circle to jerk off onto a piece of pita bread. The last one to finish has to eat it in its entirety. As seen in Drawn Together
A bunch of guys stand in a circle with a dookie in the middle. and then they all have to ejaculate onto the dookie and the last guy to cum has to eat it. Hence the "ookie".
Gabe, Josh, and Jackson came over, and we engaged in a spiritedround of ookie dookie.