whats the best joke you heard today ?

Here it goes: There was a king with three sons. He's so ill that his advisers told him its the right time to choose his successor. So the king put the three princes to a test. He sent them to a jungle in amazon and whoever came back first will be held the next king. Unfortunately, these three princes were held captives by an amazon tribe. The three princes negotiated for their release and got a deal. The amazon leader agreed that they would set the princes but first they have to get any fruit in the jungle and bring it back to the tribe. The princes hurriedly went their way to find any fruit. After a couple of hours the first prince went back. He brought an apple and gave it to the tribe leader. The tribe leader then said, "Now that you got your fruit, put it inside your as*. If your face show any reaction then we'll kill you." So the first prince tried putting the apple in his as* but his face showed a reaction and e was immediately killed. The 2nd prince came back with a grape. He gave it to the tribe leader and the tribe leader told him the same condition he told the first prince. The 2nd prince, frightened of losing his life, tried putting the grape up his as*. As he was about to do so, he suddenly blurt out laughing. Can you guess why?