UPDATE: Life & Style reports that another man, Crystal's songwriting partner Jordan McGraw, came between Crystal and Hef. The magazine first spotted Crystal and Jordan, who is Dr. Phil's son, getting cozy at the Chateau Marmont in March. Crystal denies the relationship is romantic.
PREVIOUSLY: Hugh Hefner has confirmed: he and Crystal Harris will not marry this Saturday as planned.
"The wedding is off. Crystal has had a change of heart," he tweeted on Tuesday.
Meanwhile Crystal's camp claims the decision was mutual.
"It's very sad," her music manager Michael Blakey told E! News. "It was amicable."
Earlier in the day TMZ reported that Crystal, 25, moved out of the Playboy mansion and decided to cancel the wedding after she and Hef, 85, had a nasty argument over the weekend.
The couple was engaged at the end of last year and enjoyed some red carpet PDA during the spring.
Just earlier this month, Hef explained to UK's Metro magazine how he maintains a relationship with a woman 60 years his junior.
"If you're in good health, age is just a number," he said. "I'm consistent; when I was 20 I was dating 20-year-old girls and now I'm 85 I'm still dating them."