The ex-boyfriend is a subspecies of the human male ( Imbiliciis Moronii a. Prickus ), known for once having been your boyfriend before he left you for another girl (most likely younger, prettier, thinner and all round nicer), or before you tired of playing with the smallest attachment in history and decided to upgrade to a newer model. Virtually all males can be classified as ex-boyfriends ( or ex-girlfriend, depending on their age and what they look like after you're done with them); other than Bill Gates, Wikipedia administrators, and janitors.