Pulling a Konsker

a fatal move in competititve sports or military operations that will ultimatly result in your team losing or being slaughtered by the enemy

Captain Fawcett: Private Jonesy is trying to juggle live grenades in the middle of a firefight.

Lieutenent Repperton: Good Lord, somebody stop him before he pulls a konsker!

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Steve Bartman is known for pulling a konsker on the Cubs, and now every Chicago fan hates him.