An obese woman, preferably 260+ lbs., who happens to be a slut. This woman ends up pimping out at least 2 younger males, too drunk to comprehend what they are doing, and takes advantage of them. The next morning, the Big Kahuna tells all their friends what happened the night before, causing embarassement and hilarity.
"Hey man, I heard you hit the Big Kahuna!"
Or simply, do the hang loose sign and say "Big Kahuna" to her victims.