At its core, this phrase appears to describe a humorous, perhaps absurd, scenario involving a "gal" (a type of girl) and an unfortunate incident related to her backside. The term "cracked" at the end suggests that the story or joke has been somehow broken or revealed.
At its core, this phrase appears to describe a humorous, perhaps absurd, scenario involving a "gal" (a type of girl) and an unfortunate incident related to her backside. The term "cracked" at the end suggests that the story or joke has been somehow broken or revealed.