this entire scene is pretty classic but the relevant part begins around the 0:45 mark. Also note the scotch they order is a "33" year old scotch.
https://www.businessinsider.com/order-a-beer-like-a-german-2014-3
Inglourious Basterds
There's a scene in Quentin Tarantino's "Inglourious Basterds" where a British spy outs himself simply by ordering a drink.
Without giving too much away, the spy, undercover as a German officer, orders another round of whiskey, telling the bartender, "Drei Gläser" (three glasses) and holding three fingers up — his index, middle, and ring finger.
Suddenly, the jig is up. The British spy realizes he has been outed as an imposter , and the entire bar erupts in a firefight.
A true German would have ordered "three" with the index, middle finger, and thumb extended. This is the common way that most Western Europeans (such as Germans, Austrians, Belgians, Italians, the Swiss, the Spanish, the Dutch, the Portuguese, the French, and Scandinavians) count with their fingers, and it also extends to how they order drinks, according to a 2009 study from the University of Alberta-Augustana .
When counting, the thumb is always the first digit and represents number one, followed by the index finger (2), middle finger (3), ring finger (4), and finally the pinky finger (5).
hand finger counting