When one performs or lets loose what he/she thinks to be a fart, and turns out to be a little wet turd that is squishy and warm between the cheeks. If left unattended, this mush may become rather irritable, uncomfortable, and smelly. This always results in a mess and sometimes may soil one's undergarments. One may relate this occurrence to a real life cab drivers ass.
Dude, totally have to change my boxers I got cab drivers ass.
What in SAM hell is that smell, Brian you got cab drivers ass again?