It's the act of placing one's naked ass onto someone's resting hand after using the bathroom and not wiping the behind.
that's disgusting!!! Mark gave me a POO STAMP while i was talking to Amber , now my hand smells like shit!!!.
when a man or a women shits hot diahrrea, then rubs their ass in it and stamps shit prints on objects or even people as a practical joke.
Last night, we pulled the best prank on Jake. Kyle poo stamped his bed, couch, and his sink hahaha so gross!