Mocha Marks
A line of fecal matter in your underwear that varies in thickness from thin to meaty. Usually a result of poor asswiping skills.
I farted and left mocha marks in my drawers.
Mocha's Mark
A Mocha's Mark is when you fart in someone's face and then run off and vomit on their bed.
Dude, I need to wash my face and blankets because your dog just gave me a Mocha's Mark.