sly goose 

A master of the art of conning.

That hamburglar is a real sly goose.

sly goose by java monster February 22, 2008

sly goose 

When an otherwise ladylike female subtly lifts one cheek in order to decompress air from her derrière. A skillful practitioner will couple this art with conversation or laughter as to dissuade any suspicion should the tuft of air carry an unpleasant odor.

George: Did somebody just fart?
Nancy: I think Rebecca pulled a sly goose.

sly goose by Rozu May 5, 2011

Sly Goose 

An Act were two friends engage in sexual intercourse behind the back of others.

" Jimmy got gripped in the back of his motor with Steve's Bird getting blew off, apparently he'd been giving her the Sly Goose for a while "

Sly Goose by John Gaskell March 24, 2004