A particular variation of the "group poop," where two (preferably) male members expel fecal matter simultaneously in the two stalls next to each other on the third floor of the Sigma Chi fraternity house in Beloit, Wisconsin. In addition to the poop, one brother may play "ambient radio" on Pandora to give the environment an added sense of peace and tranquility. However, before the action is to take place, brothers must sign up for cross dumping times so that they are assured a cross dumping partner.
Athi: Kyle, how was cross dumping with Davecat?
Kyle: It was weird. He kept asking me if I enjoyed the wraps with aioli he made earlier... The only response I gave him was the sound of my entire insides being shat out.

Kyle (to numerous people in the room): You tryin' to cross dump?
Eddie: Yeah, give me a minute. You tryin' to bun first?
by DavecatDaCrossDumper February 23, 2012
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