Halla balla is a Norwegian slang for greeting someone in an old jolly way and it is funny say, because it rhymes. But you should not say it in a job interview for example. Halla is slang for hallo, and means hello, while balla basically means balls.
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