noun. A person, possibly a friend or ex-friend, who completely blows up your chances of entering a vagina, causing millions of sperm voices to suddenly cry out in terror and suddenly become silent.
"I would have tapped that if mufftarkin over here didn't tell her about the time I sharted myself in the gym."
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