A farmer and his pig

A farmer and his pig were driving down the road when a cop pulled him over. The cop asked the farmer, "Didn't you know it is against the law to ride with a pig in the front of you truck?" The farmer replied, "No, I didn't know that." The cop ask the farmer where he was going and he said, "To Memphis". The cop said, "I will let you off the hook this time if you promise to take the pig to the zoo when you get to Memphis." So the farmer promised he would. Several days later the cop spotted the farmer with the pig driving down the road and he pulled him over again. The cop said "I thought I told you to take this pig to the zoo when you got to Memphis" and to this the farmer replied "I did and we had so much fun, I'm taking him to the circus."