A person that flutters around from person to person flirting with them, and trades from person to person like a bird fly's from telephone line to telephone line.
"Liz, you are such a flirt-bird! You're constantly flirting with every guy you talk to!"
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