Flash Cocktail

The performer displays two transparent empty glasses and his hands completely empty. Both glasses are placed on each other mouth to mouth. 

He holds the glasses like a cocktail shaker and moves it as if making a mixed drink. The Glasses are shaken, and visibly fill with a colored liquid.

The glasses are taken apart, the magic drink can be served. Nothing is to be hidden on the body or at the table. Nothing to steal, nothing to palm, to swap or to fumble.