When one takes his/her soiled underwear and then precedes to take their underwear off, facing the soiled portion towards the other persons chest and slapping it on their chest.
"Did you hear about Sally getting a Flap Jack Surprise the other night from Tom?"
by Awesome Pants March 24, 2007
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When 2 or more people stuff pancakes up their asses, take pictures of it and send it to their parents
Person 1: Dude my mom got a sick Missouri Flap Jack Surprise this morning!
Person 2: Nice i gave one to my dad the other day, it was awesome!!!
by jdan916 May 16, 2011
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