A man walks into a bar and sees a sign that says, "Free drinks for the person who can make our horse laugh."
The man thinks to himself, "I can do that," so he walks over to the horse and whispers something in its ear. The horse immediately starts laughing hysterically, snorting and neighing with joy.
The bartender is amazed and gives the man his free drinks. As the man is enjoying his drinks, the bartender asks, "What did you say to make the horse laugh like that?"
The man replies, "I told him that my ex-girlfriend was going to come in and pay for all his drinks!"