A move made famous in the movie
Dumb and Dumber To. Harry and Lloyd attend a party at a science convention. They do not realize the drinks are free, so they walk around taking half-consumed
beverages and combine them into a glass as a full drink. They stick their hands into their nasty assholes and then swipe their ass juice around the rims of their glasses. They then proceed to tell a convention worker that the
beverages are bad and they have her smell and inhale their ass stank to get new, fresh drinks. They refer to this action as The Old Stinkeroo.