Two explorers crash in the jungle.

They were flying over it when a reactor of their plane started malfunctionning; the plane crashed.
The two explorers were rescued by a local, cannibal tribe.

"We going to eat you" the leader said.
"We not eat you if you do challenge."

"What's the challenge?" Said the pilot of the plane.

"You two go in jungle and bring back ten fruit."

The two hostages ran I to the jungle and started picking up fruits. One of them got all the fruits needed and headed back to the camp. He had brought back ten tiny red fruits of which he did not know the name. The leader then says to him:

"Now you shove them up ass and you no laugh and no cry."

So, confused, the explorer started doing the weird thing the man asked him.
One, two, five, eight fruits, and at the ninth fruit he bursts out of laughter.

"You were so close of goal! Why did you laugh?" The tribe leader asked.

"Well, over there I can see my friend bringing back watermelons".