What does ass mustard assmustard mean?

ass mustard assmustard meaning in Urban Dictionary

The brownish-yellow discharge within a person's undergarment after a night of processed foods and/or bad alcohol. It may be delivered by flatulence, or a stable leak. 1. developed after rectal intercourse, the substance which seeps from rectum (mostly semen and feces combined) which can be commonly used as a condiment.2. The compound produced whenever one made use of any condiment as an anal lubricant.