The term that is used for someone willing to take the seat of a (usually) retarded person who calls "shotgun" in an attempt to obtain the front seat of a vehicle. However this must be said within a split second subsequently after the first person calls shotgun.
Person 1: "I call shotgun!"

Person 2: "Well I call double-pump shotgun, better get in the back of the van or it's gonna be one hell of a ride for you."
by ogdajuiceman January 31, 2011
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