Crystal Harris "didn't feel comfortable" knowing Hugh Hefner had other women in his life.
The 25-year-old model - who called off her wedding to the Playboy boss less than a week before the planned nuptials tomorrow - had second thoughts because of monogamy issues and only said yes to his marriage proposal because he asked with a crew of cameramen.
She told US TV show 'Entertainment Tonight': "I wasn't the only woman in Hef's life. I didn't feel comfortable in my heart knowing that and getting married to him, because a marriage is between two people. That's not what our relationship was.
"It happened so fast. Hef asked me to marry him in front of three cameras and a photographer. I thought it was something I wanted."
Hugh, 85, has continued to get over his heartache by enjoying romantic comedy movies at the Playboy mansion with the other Playmates living there.
He tweeted: "Anna invited some of the playmates over to watch a movie to cheer me up. Anna, the girls & I watched Adam Sandler & Drew Barrymore in "50 First Dates" tonight.(sic)"
Meanwhile, Hugh's ex-girlfriend Kendra Wilkinson thinks the magazine mogul needs "time to breathe" after the break-down of the relationship.
She said: "I'm leaving him alone right now. He needs time to breathe and grieve. Obviously I feel really bad for him and the situation."