Little bits of shit (feces) that get stuck to your ass (or elsewhere on your body) that could possibly be mistaken for freckles, but upon closer inspection are revealed to be "shit freckles".
At first I thought that Mary had a nice freckly ass, but upon closer examination I saw that her ass was just covered with a bunch of nasty shit freckles!
If you are eating out a girls ass and she spray farts all over your face.
I decided to eat my girl friends ass last night and she farted shit freckles all over my face. Damn, I'll never do that again!