Crusty Finger 

A Crusty Finger is when the toilet paper splits and your finger passionately pierces your rectum, and you forget to wash your hand so the poo becomes crusty.

My mate ate a sandwich with a crusty finger.

Crusty Finger by ISadlyHaveNoLife September 3, 2016

crusty finger fungus butt

school yard taunt. Denotes the person is icky

"that Tommy is a crusty finger fungus butt"

crusty finger fungus butt by Peter Rothe March 6, 2008

Crusty Finger Duster 

When someone uses their dirty and scabbed hands to perform secual gratification in return for goods or services. No lubricant is used and typically the scabs from the 'Duster' will fall onto the genitalia of the person they are dusting

Dude, Lauren is outside of Pilot giving a Crusty Finger Duster for a pack of cigs and enough gas to get home.

Crusty Finger Duster by MadDawgShorty July 30, 2021