Shit eating grin. I can't say about possible ancient origins but I can say something about my own personal experience with the saying. I had a Dog when I lived in the mountains of Colorado, that was a bad ass. He would even chase bears away. Every so often he would dissappear for a couple of days. He would go on a "walk about" and go to ranches and eat cow and horse manure, which is chocked full of vitamins. When he showed back up, I would ask where he had gone and wouldn't look at me, he would look to the sides, knowing he had done something bad. He also had a full teeth actual grin from ear to ear, he also would have manure all over the hair around his mouth. I believe this saying really got going from farmers with dogs. This saying lends itself well to someone in a board room, when the jerk throws someone under a bus. Lionatlarge thx. Lionatlarge (talk) 00:47, 2 October 2024 (UTC)