Today on the Metro, I watched as an otherwise respectable looking lady scraped the inside of her nose with her fingernail, examined the green gook the job left on said fingernail, and proceeded to put it in her mouth.
Not surreptitiously, mind you, but slowly and deliberately, with a bit of bravado. The way one might eat a piece of savory chocolate or a slice of finely aged prosciutto.
And then she did it two more times. Cause it was so tasty.