A camel and a dromedary are alone in a desert talking to each other.

The camel starts laughing.

“Why are you laughing?” asks the dromedary.

“Because you have a hump on your back!” replies the camel. “It looks so funny on you.”

The dromedary confused and a bit embarrassed looks at the camel. He does not know what to say. Then, after a moment of thought remarks “And you, have two.”

The camel taken aback stops laughing. He had never seen that he had two humps.