Hugh Hefner and Crystal Harris: The Wedding's Off!

Octogenarian publisher and his 20-something bride-to-be decide not to marry

Cancel your trip to Hugh Hefner and Crystal Harris' wedding on Saturday, because the nuptials have been called off.

Hefner made the announcement via his Twitter account on Tuesday, writing, simply, "The wedding is off. Crystal has had a change of heart."

According to TMZ, the "Playboy" empire mogul, 85, and his latest lady-love, 25-year-old Harris, broke it off after a heated argument over the phone on Sunday. (Specifically, according to sources, Harris called off the wedding and moved out of the mansion after the fight.)

Harris offered a cryptic message that seems to pertain to the breakup on her Twitter account Monday, writing, "There are two mistakes one can make along the road to truth…not going all the way, and not starting.”

Radar Online reports that December 2009 Playmate of the Month Harris has is now dating Jordan McGraw, son of TV advice-dispenser Dr. Phil McGraw. A source familiar with the couple tells Radar, "She thinks she is going to be living with all of Dr. Phil's millions." Harris and McGraw were reportedly spotted cozying up with McGraw in March at Hollywood hotel/hanout Chateau Marmont.