Scooby Doo Logic 

The concept of, whenever something bad or sketchy happens, splitting up. It was originally applicable in the to moments in the show, Scooby Doo, when the gang was in a group and then splits up to gather clues (often with moderate success and then complications, e.g. Velma loses her glasses). Usage now, though, has come to generally be in regards to two or more people separating, or "splitting up," when it seems illogical to do so.

"What the fuck? You're breaking up with me?" said the boyfriend.

"Yes," said the girlfriend.

"I can't believe that you're splitting up with me! This shit is fucking Scooby Doo Logic!" he screamed.

Scooby Doo Logic by Oodles and oodles of noodles! April 8, 2012