When a person or recognised group is described in a manner that opposed one's viewpoint in an incredulous or sly manner. Depending on context can also be used as a placeholder noun for a situation that is disadvantageous for one's self, resorting to fantastical and illogical solutions.
Person 1: Man, that test was so hard.
Person 2: I know right? Elijah Wong was boasting about his grades after the test. So I pulled a chinky binky on him.
Person 1: So what did you do to him?
Person 2: I ate his dog.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi