ass mustard
The brownish-yellow discharge found in one's undergarment after an evening of junk food and/or bad beer. It can be delivered by flatulence, or a steady leak.
Boy howdy! your drawers are loaded with ass mustard!!!
Hot Yellow Ass Mustard
Hot Yellow Ass Mustard: the result of anally straining oneself beyond one's limits then exposing that matter to a heated element.
After we ate the bean burrito we had a farting contest in which Matt pushed too hard and sprayed ass mustard all over the space heater causing it to become hot yellow ass mustard.
Mustard Ass
Someone whose ass emits an odor strong enough to create casualties reminiscent of WWI's Mustard Gas.
Mike 'Mustard Ass' Dukes, has a weapon of extraordinary proportions in his arsenal.