Rather than forcing people to choose either water or wine, the Alliance wine and water glasses by design students Florence Louisy and Léo Schlumberger encourage a healthy balance of both beverages.
The hand-blown glass pieces are designed to sit atop one another, with the wine glass perching atop the wider water cup. Since each beverage gets its own glass, there is no contamination, but the idea is that for every glass of wine that's had, one should indulge in a glass of water afterwards. If the bottom glass is filled with ice, it also aids in keeping the wine nicely chilled. Louisy describes that "By combining two glasses, the idea of alcohol is linked to the one of water," and since both glasses can easily be held in one hand, consuming both beverages one after another is hardly a hassle.