A Priest is nearing the end of his tour of duty and about to leave his Mission in the jungle where he'd spent years teaching the natives, when he realizes that the one thing he never taught them was how to speak English.
So he takes the chief for a walk in the forest, points to a tree and says to the chief, "This is a tree."
The chief looks at the tree and grunts, "Tree."
The Priest is pleased with the response.
They walk a little further and he points to a rock and says, "This is a rock."
Already starting to get the hang of this, the chief looks and grunts, "Rock."
The Priest was getting really enthusiastic about his progress when he suddenly hears a rustling in the bushes.
Peering through the dense vegetation they see a couple of natives in the midst of some pretty steamy sexual activity.
The Priest immediately goes bright red and quickly responds, "Man riding a bike."
The chief looks at the couple, pulls out his blow-pipe and kills them.
The Priest goes absolutely ballistic and rants at the chief that he's spent years teaching the tribe how to be civilized and kind to each other, so how could he kill those people in cold blood that way?
The chief replies, "My bike."