Literally: to be Fanny
Meaning: To lose a game without having taken any point;
Origins: 19th century, still used, mostly in sports.
Originated with the pétanque game in Lyon. A girl named Fanny, from the Croix Rousse district was known to console the loser of a pétanque game by lifting her skirt.
Later,” to kiss Fanny” (to kiss a woman’s picture or a statue’s buttocks).
The loser, consoled, would be a happy loser.