A fork of Rural Dictionary
something you say when someone lies to you, cheats on you, betrays you
john: i love you anna.
anna: don't piss down my back and tell me it's raining!
A feeble, weak specimen of a human being who when he needs to urinate must adopt a "sit down position" due to him having a maggot sized penis hence the saying sit down pisser!
Mark kicked open the toilet cubicle door to find Elliot having a "Sit down piss".
His penis was so tiny that he couldnt hold it to urinate, he had to "sit down for a piss".