. . . when you find out the boy you dated for a year and a half, and were very much in love with, and with whom after an amiable break-up you have stayed close friends based on the theory that he was just a little immature and needed to grow up (and even though he was horribly emotionally abusive to you, you made such-like excuses for him) and it just didn't work out because of timing, when in fact he was lying and cheating all along and was actually not just kinda a doof but a REALLY TERRIBLE PERSON?
You listen to The Gossip really fucking loud and sing your heart out and dance around in your bra, that's what.