It's only fitting that if the engagement is announced over Twitter, the breakup should also be announced over Twitter. Hugh Hefner tweeted Tuesday that "the wedding is off. Crystal has had a change of heart." Sources said Hefner, 85, and Crystal Harris, 25, supposedly had a "nasty argument" over the weekend, and Harris moved her things out of the Playboy mansion pretty much immediately—only a week before the wedding. The ceremony was also scheduled to air on Lifetime on July 13. Although Hefner tweeted that Harris took their dog, Charlie, with her when she left, he seemed to be taking the breakup in stride, tweeting, "Since we're not getting married on Saturday, I've scheduled a movie: 'Runaway Bride.' Seems appropriate." Maybe he's already found some outside comfort: One of the "Girls Next Door," Bridget Marquardt also came over to "give her loving support."