Spanish Delicacy

One day an american guy visits spain.after watching an exciting bull fight,he goes into a restaurant for dinner.while he waits for his meal, a waitor walks by with a steaming plate of food. the american guy asks the waitor what it is. the waitor relpies that it is bulls testicles from thefight. wlling to try anything once, the american orders one for the next day......
the next afternoon, the american walks into the restaurant and sits down to his meal. when he sees the waitor, hetells him they are delicious, but why are they so much smaller than the ones yesterday? then the waitor tells him, sometimes the bull wins!