Greedy Cup

From Wiki- "A Pythagorean cup (also known as a Pythagoras cup, a Greedy Cup, a Tantalus cup or as o kounenos tsi dikaiosynis) is a form of drinking cup that forces its user to imbibe only in moderation. Credited toPythagoras of Samos, it allows the user to fill the cup with wine or any other liquid up to a certain level. If they fill the cup only to that level, the imbiber may enjoy a drink in peace. If they exhibit gluttony, however, the cup spills its entire contents out of the bottom (onto the lap of the immodest drinker)".