When one sneaks up behind another and starts from the bottom of their legs and kind of "swims" their hand from leg to leg at a fast pace up their leg. The objective of the slippery salmon is to startle the person and make them feel awkward and as if they were raped. However, try not to touch the persons genitilia region as that persom might think you are a "fag."
Justin snuck up behind Travis and gave him a slippery salmon as a prank.
by mikebrown97 May 17, 2012