The Rusty Pirate is when you're banging a chick in her shit pipe from behind and then proceed to further own her whorish soul by reaching into her mouth with your index fingers and applying the always effective and potent technique known as the double fish hook. But wait, there's more... you then add the audible tone of "Arrrr, walk my plank you Sea Donkey!"
~ The End
After my date gave me the Rusty Trombone, I felt the need return the favor and proceeded to give her the Rusty Pirate. Arrrr!!!