A crusty knuckle is when you have your girl stimulate your prostate by shoving her middle finger up your anus. Look at her knuckle once she is done.
by John Chapman June 1, 2007

by What's Poppin November 21, 2016

person 1: “have you seen Ava’s nan?”
person 2: “i know she’s literally the definition of a crusty nan”
person 2: “i know she’s literally the definition of a crusty nan”
by smellywelly16 April 17, 2022

by ham s-wich February 19, 2021

by anonymous July 6, 2021

by Carol_thebomb November 17, 2020
