One day, a man walks into a bar and sees a sign that says, "Free drinks for anyone who can make our horse laugh." Curious, the man asks the bartender about the sign and the bartender explains that their horse, named Sparky, has never laughed before.
So the man decides to give it a shot and walks over to Sparky. He whispers something in Sparky's ear and suddenly, the horse starts laughing uncontrollably. The man goes back to the bartender to claim his free drinks and the bartender is amazed.
A week later, the man comes back to the bar and sees a new sign that says, "Free drinks for anyone who can make Sparky cry." Intrigued, the man goes over to Sparky again and whispers something in his ear. This time, Sparky starts sobbing uncontrollably.
The bartender is astounded and asks the man how he did it. The man replies, "Well, last week I told Sparky that my horse is bigger than him. And today, I showed him."