When, in cases of extreme thirst, a person using a soft-drink fountain fills the beverage container, chugs it, and then fills it again before sitting down to eat.
Person 1: Hey man, why did it take you so long to get a soda?
Person 2: I was prefilling my cup; I've been thirsty all day.
Person 2: I was prefilling my cup; I've been thirsty all day.
by Matt Coon August 7, 2007