Fool your friends with a more modern version of the Pythagorean cup. This cup have in the background a small hole when beginning to fill the cup, it behaves like a normal cup but when the level reaches a certain threshold, the liquid begins to flow out of the bottom of the cup until this one is empty
3D printing helps make the traps more discreet in concealing the mechanism of this one in the glass edge
dimentions: Height: 190mm Max diameter: 126mm