The art of female vaginal gas release (a parp) whilst defecating at the same time (shitter). To be a true parpy mcshitter, the women must do this act into a Mcdonalds Mcflurry icecream container. Then a straw or other eating device can be added and served to the customer.
I was up at Gregs house and he made his girlfriend do a Parpy Mcshitter. We then went to Mcdonalds and snuck it into the Mcflurry tray.... I believe a small child died.