when your jaw gets tight and soar after going down on a girl for too long. it shouldn't take that long. maybe you should take a breather, let her bear the burden for a bit. Then your cunt jaw will get better and you'll get a blow job; everybody wins!
Person: "what happened to your eye?"
Guy: "My girlfriend punched me in the face because I couldn't get her off."
Person: "That sucks."
Guy: "The worst part is I've got fucking terrible cunt jaw."