I recall watching the Orangutans at Toronto Zoo in the 1970s....they had a large enclosure with a small 'stream' running through it. One of the 'teenage' Orangs was being pestered by a younger family member who wouldn't leave him alone.
The 'teen' went and sat with his back to the younger one, and unbeknownst to the latter had one hand down in the water.
As expected, the young one started creeping up....the teen didn't let on that he was aware......but at the last second spun around with a handful of water and soaked the young one. They have a sense of humor.