The first guy says "I have the smallest arm in the world. The second guy says I have the smallest head in the world. The third guy says I have the smallest penis in the world. They all go to the Guinness Book of World records. The first guy comes back and says I really have the smallest arm in the world. The seconds guy returns and says I have the smallest head in the world.
the third guy comes back and angrily says WHO THE HELL IS JUSTIN BIEBER