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".