To be balls deep in your girl, and then you take two fingers and insert them into her anus and form a hook with them. Use those fingers to anchor her down as her legs are wrapped around you.
Jim - "Hey fred, so i was balls deep in your mom last night..."
Fred - "Did you give her the 'Great Canadian Fishhook'?"
This is when you attempt to anally fist a large, burly, unshaved woman using only maple syrup as lube while Oh Canada plays softly in the background.
Ex. I was at the Hosher Hut last night and met an amazing women. She took me back to her place only to crack open some maple syrup and try The Canadian Knuckle Buster.