Crystal Harris & Hugh Hefner Call Off Wedding

Hugh Hefner and Crystal Harris have called off their wedding.

"The wedding is off," Hefner, 85, tweeted Tuesday. "Crystal has had a change of heart."

After getting engaged on Christmas Eve last year, the Playboy founder and Playmate reportedly had an argument over the weekend; according to TMZ, Harris moved out of the Playboy mansion and canceled Saturday's nuptials.

UPDATE: Harris' rep, Michael Blakey, "spoke to Crystal earlier this morning and she had shared the sad news with me," he tells Us Weekly. "The breakup was amicable. Crystal will now be focusing on her music career and her new single 'Club Queen,' which was released today."

Prior to Hefner's Twitter confirmation, Harris hinted: "...