What's on your back?

A German, an American, and a Mexican are traveling in the Amazon, and they get captured.The head of the tribe says to the German, "What do you want on your back for your whipping?"The German responds, "I will take oil!" So they put oil on his back, and a large Amazon whips him ten times. When he is finished the German has these huge welts on his back, and he can hardly move.The Amazons haul the German away, and say to the Mexican, "What do you want on your back?" "I will take nothing!" says the Mexican, and he stands there straight and takes his ten lashings without a single flinch."What will you take on your back?" the Amazons ask the American. He responds, "I'll take the Mexican."