The are so into and proud of themselves that if they were to shit right now, they would eat it.
A smile where the person is so full of it that you want them to “eat shit” (you hate it)
According to urbandictionary, if someone is shit eating, it means “To be exceptionally smug, full of oneself.”
I guess, it’s a type of grin that makes someone assume the person is like that.
I know what it means. I don’t know what it has to do with consuming feces.
According to this source via wiktionary, it’s ‘[p]ossibly from a contraction of “grinning like a ’possum eating shit.”’
Hm that kinda makes some sense. I have to wonder who ever saw a possum do that though. They aren’t much for being seen :)
I figured it came from a similar expression like “happier than a pig in shit” implying the person is happy about something they really shouldn’t be happy about.
