A condition afflicting a newly single woman, in which all the annoying attributes of her exboyfriend that she ignored while dating him are magnified by 10 after they break up. She finds spending any amount of time around him unbearable. Symptoms include: excessive bitching, muttering expletives under her breath, picking apart everything her ex says, and extremely annoyed friends. The only cure for exboyfrienditis is distance from the source of the disease.
"UGH Brad is such a pretentious asshole. He thinks he's god's fucking gift to humanity!"
"Whoa, chill out. You've just got a bad case of exboyfrienditis."
Pretty much any of one's exboyfriends. They are all evil or they wouldn't be exes. If you start re-dating one of them, don't say I didn't warn you. Do as I say, not as I do.
"My evil exboyfriend spread rumors that I was stalking him to make himself look desirable."
The case of an ex fling showing up out the blue, knocking at the door, calling or texting, and in all seeming innocence, asking you out for coffee, a bite or a drink "to catch up." Often they are married and what is really going on is that they are trying to see if they've still got it.
"Today I had a knock at the door and it turned out to be nothing but an innocentcase of exboyfrienderuptus"
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