Hugh Hefner says he waited more than a decade to file for divorce “because of the children.”

Last Thursday, the Playboy founder filed paperwork to dissolve his 20 year marriage to former Playmate of the Year, Kimberly Conrad Hefner. The couple married in 1989, and have been legally separated since 1998. Over the past decade, Hefner lived with numerous girlfriends at the Playboy Mansion as part of the E! reality show The Girls Next Door.

Now that the former couple’s sons, Cooper and Marston, are of age, Hefner, 83, says, “Now is the time.”

“I stayed married not because it was a marriage — the marriage ended in 1998,” Hefner said at the premiere of his documentary, Hugh Hefner: Playboy Activist and Rebel, at the Toronto International Film Festival on Saturday. “I stayed because she wanted me to.”