Wine and Jealousy

Louise and Kate decided to spend the evening over a glass of wine. But when the waiter brought just one last glass of red, the atmosphere became tense. I ordered first! Louise exclaimed. You? You don't even know the difference between Merlot and Cabernet! Kate replied. While they were arguing, the waiter imperceptibly poured white wine into both of their glasses. The friends sitting nearby laughed for a long time, and Louise and Kate eventually united... against the waiter.