It's the water

 

In an Italian café they will ask if you want water and if you do, do you want it fizzy or flat? Pellegrino bottled near Lake Como is the fizzy of choice although there are others. Pellegrino comes with a special cap so if it is opened and someone tries to reuse the bottle you can tell. In France it is Perrier and both are imported to the U.S. by Nestle. I prefer fizzy over flat.