The Expedition is the sexual act of placing two in the front and six in the rear. Normally accomplished by placing the index and middle finger of one hand in the vagina and the pinky finger of the same hand and the entire other hand in the anus of your partner (lube optional). A derivative of the minivan where 2 are in the front and only 5 in the rear.
"Dude, my girlfriend is so loose in the trunk now the Minivan doesn't cut it. Last night I went with The Expedition on her ass."