During anal sex, the pitcher pulls out, spits on the catchers back. At which point the catcher will turn around allowing the pitcher to lob a stream of baby juice in the catchers eye. After recieving the eye candy, the catcher will cover up the affected eye with their hand. The crucial point for the pitcher is the timing of the last step: expertly landing a heel stomp to the toes of the catcher. The catcher will then be covering one eye and hopping on one leg.
Nobody ever said the life of a one eyed, one legged pirate is easy.