In this Amstel commercial, you see three guys in a bar having discussions about a woman. They are in doubt whether she is in fact a woman, or a transvestite.
In order to check this, one of the men walks up to her, and asks her a question about soccer (when is a player off side). The woman immediately gives the correct answer, which leads the men to the conclusion that it has to be a trans- vestite, hence a man.