Chinese and American are in a plane.
Suddenly, Chinese puts his shoes off and American is angry.
After some time, he goes to buy a coke, but Chinese says that he'll do it.
While he's gone, American spits into his shoes.
Chinese gets back and American drinks his coke.
That repeats a couple of times,and after the flight American admits, "I spitted in your shoes, sorry."
Chinese answers, "That's how we do it. We spit in each others shoes, we piss into each others cokes..."