When you place a large helping of mashed potatoes into the ass crack of your individual of choice. Then you spray your "Man-Gravy" onto the mashed potatoes and proceed to eat them out of your partner's ass. If Beef Wellington is involved, the partner shits into the Mashed Potatoes the entire load.
Kyle iinvited me over for dinner. He failed to tell me that Mashed Potatoes Man-Gravy was to be our dessert. Of course, I surprised him with a little Beef Wellington on the side.