A popular term used by people to insult the punk-rock band Green Day. Although it has been debunked, people still continue to use it as a mock towards Green Day fans.
"Green Day, more like Green Gay."
"The members are bisexual you absolute fuckingwalnut."
"Oh."
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