A fork of Rural Dictionary
When one has to take such a long and lengthy piss after holding it in for an absurd amount of time. This piss mimicks one that would come out of a massive horse cock (Thick and Steamy), although it is coming out of your average human schmeckle.
Gary “I’ll be back boys, I have to go take a huge horse piss with my rhino chode.”
Horse-masking is an erotic practice in which you pee into a horse mask and place it on your head(usually practiced while taking edibles).
Guy: "Yo what you doin tonight" Horse-masker: "Imma just be chillin with the bros doin a little horse-masking"