Hugh Hefner and Playboy playmate Crystal Harris will not be tying knot this weekend as planned. Hef just tweeted, "The wedding is off. Crystal has had a change of heart."

Reports claim Hefner, 85, and Harris, 25, got into a huge fight over the weekend resulting in Crystal pulling the plug on the nuptials. As for the wedding, it was to take place this Saturday at the Playboy mansion and over 300 people had already been invited!

Harris, who was to wear a pink Romona Keveza wedding dress, has reportedly moved out of the mansion.

Ironically, the gorgeous blonde recently taped a Funny or Die video about the 60-year age gap between she and Hef. Watch it ... after the jump.