A sexual act originating from the Shang Dynasty in China. The upside down chinatown consists of an asian female filling her snatch with rice and soy sauce and laying backwards to her partner. Her partner then proceeds to eat out her filled vag. The act originally was intended to be performed between two asians but over time it has transcended into modern culture, including spinoffs like using chopsticks and incorporating other ingredients like sweet and sour pork.
Josh: Hey Zach how was your date with Pam last night?
Zach: Oh it was great. Did you know she's Korean?
Josh: No way did she tell you?
Zach: Well I pretty much figured it out when she gave me an upside down chinatown.
Josh: Haha score bro!
From the 1974 Roman Polanskifilm written by Robert Towne and starring Jack Nicholson. Chinatown refers to a situation in which helping makes things worse; an unintended consequence the exact opposite of what was desired; a trauma that keeps repeating itself; a character flaw that keeps re-emerging.
"Aid Syrian rebels and stop Assad? Forget it, the whole region is Chinatown."