narragansett knuckle
The sexual act when a partner takes a clam shell, inserts one half into the vagina and the other half into the anus. Once inserted, the clam holder must go knuckle deep in both vagina and anus and make the clam shells meet to make a clapping sound.
Aye, she was a salty sea hag, so it was customary to give her the ol' narragansett knuckle!