Whenever someone takes there finger and dampens it with saliva just to stick it up some body's nose.

A wet nilly also isn't limited to just using saliva. For example a person may also use some sort of spices, melted cheese, or really just whatever you want. In that case the word "wet" is replaced with any of what you are sticking up a persons nose.

"Cheese Nilly"
"Garlic Nilly"
"Ass Nilly"
Don: Hey why do you have that fish stick covering your finger?

Peter: HAHAHAHAHAHAHAHAHAHAHAHA

...moments pass

Nick: Nooo Peter please not a wet nilly

Don: Nick yo must be confused. It's actually a fish stick nilly.
by xxxbetterthanyouxxx September 29, 2009
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Sticking either your wet finger or tongue into someone's nose surprisingly
I stuck my tongue in my mates nose and gave him a wet nilly
by wolftone1916 November 19, 2020
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