1) Insult your previous friend to a new extreme of humiliation. Use insults that do not necessarily have to be funny, but hurtful, words that will effectively break down the person's self will. To further intensify the ridicule, create a nickname for said 'ball dropper' that will always and forever refresh why the person will only ever be invited to events to be known as the guy who fucked up. (you fucked up chants are usually followed)
2) Never talk to them again, only talk about them when referring to them as "the stain." See "The Stain" for definition.
Joey: That blows dude, she should be fired.