To pretend to actharsh or rude to someone or to pretend to scold someone.
She behaves scrumbulous whenever mom arrives from work.
Immediately the police walked in, she became scrumbulous.
You can't fool me, I know you're just being scrumbulous
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