when you go to wash your hands and you smell something weird. then you go look in the toliet and see someone didnt flush the time befor you. (not usable in a port-a-potty)
Handpooping is what happens when your repeated attempts at shittingunder the table at your staff party's venue are foiled and you're forced to proceed with plan B.
Search "Nasty .. Toronto Woman Poops In Her Hand After Club Night And Tosses it like Nothing Happen" on YouTube.
Note: No bathrooms were harmed in the pinching of these loaves. #handpooping