A pet name for herpes, a venerial disease common among the lower classes within society. Used mainly by couples who dont wish to talk to much about someone's "dirty problem" and by friends who know the "secret code".
"Hey dude, you getting any action this weekend?"
"Nah man, my girl's got the grumpy lumps!"
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