Once the vagina has been properly lubricated, take your hairy ball sack and wipe it up and down the labia.
The name stems from the feeling of billiard balls rolling across wet felt.
"My balls itched, so I gave her the wet table felt!"
An act of a naked smaller male, hitching a ride on a naked larger woman like a backpack. The image looks similar to that of a koala cub on the back of its mother.
Dan was a Koala Backpack to the kitchen to get some snacks post coitus.