to perform the wet luigi, you must first approach a target undetected. Then, in a fluid motion, pull down that person's pants, spread they bum-cheeks, and spit inside their booty. Lastly, pull the receiver's pants back up and kick the extremely hard in the ass. Extremely good for kicking people out of houses or cars.
She was pissing me off so I kicked her out, but when she was leaving, I gave her a wet luigi.