When you put a fist in someone's ass and open your hand as wide as possible. This is also known as a "Staten Island tsunami"
by TbagMartin March 23, 2010
by Paul Hanes April 06, 2005
I couldn't tell what felt better bustin out that ass brownie or the blowjob my girl was giving me, like Hannah Montana said, "gettin a Flumper is the best of both worlds"
by Forb-Z August 11, 2010