A man goes to Spain and attends a bullfight. Afterwards he goes to a nearby restaurant and orders the specialty of the day. The waiter brings him two very big balls on a huge plate, which the tourist eats with relish.  The next day he goes to the same restaurant again, once again orders the specialty of the day, and he is brought two very big balls on a huge plate. It tastes even more scrumptious. 

The third day he does the same and the fourth, but on the fifth day he goes to the restaurant and orders the specialty of the day, and they bring him two very small balls on a big plate. The man asks, "What gives?" 

And the waiter says, "Senor, the bullfighter doesn't always win.