A slang phrase for vaping a disposable electronic cigarette.
It's a reference to Chinese factory workers who 'directly' test every stick before it leaves production line.
Youngster A: Hey dude, wanna kiss a chinaman* after school?
Youngster B: Sure man. Damn, I want to kiss a chinaman* so badly. That's the only thing on my mind since morning.
*(In some regional variations, the second part is silent)