Hugh Hefner is mourning the loss of his longtime secretary, Mary O'Connor.
The 86-year-old founder of Playboy shared the news on his Twitter page on Sunday, January 27.
"Mary passed away today," he said. "We loved her more than words can say."
"Hef's long time secretary & my dear friend Mary O'Connor has passed away," Hefner's new wife Crystal Harris, who now goes by Crystal Hefner, Tweeted. "It's a very sad day here at the Playboy Mansion. We love you Mary."
O'Connor was 84, a Playboy spokesperson told OTRC.com.
Over the years, she had established relationships with Hefner's girlfriends. She helped Harris design her first engagement ring, which Hefner bought for her in late 2010, E! Online reported. They later broke up, earning her the nickname "Runaway Bride." They then reconciled and she received a new ring. They wed on New Year's Eve.
O'Connor was sometimes seen on episodes of the E! reality shows "The Girls Next Door," which aired between 2005 and 2010 and featured Holly Madison, Bridget Marquardt and Kendra Wilkinson, Hefner's then-girlfriends who lived with him in his Playboy Mansion in Bel-Air, California, as well as on the spin-offs "Holly's World," "Kendra" and as recently as last year, "Kendra on Top."
O'Connor even hosted Wilkinson's baby shower at her home in September 2009, according to E Online. The Playboy model and reality star and husband Hank Baskett welcomed son Hank Jr. in December of that year.
"RIP Mary O'Connor. She was an amazing person who helped me through so much. But I know she's happy with her boo Captain Bob. :)," Wilkinson said on Twitter. "I said a prayer earlier for her and said an inside joke I know she was laughing at. RIP Mary O'Connor."
O'Connor's partner of 30 years, Robert Gentert, or "Captain Bob,' died in April 2012 at age 82. O'Connor was by his side.
Madison reTweeted a friend's photo of a rainbow, adding: "Rest In Peace Mary!"
"Thank you for all the sweet messages. Mary O'Connor will be missed. #RIPMary," Marquardt added.
O'Connor worked for Hefner for more than 40 years. She ran the former Playboy Mansion in Chicago, when it served as a home for the Playboy Bunnies who worked in Hefner's club in the city, before moving with him to Los Angeles, the New York Times reported in 2011.
The newspaper added that her duties included buying the fabric for Hefner's custom-made pajamas, setting up his medical appointments and keeping track of the Playboy Mansion's guest list.
The 2009 memoir "Hef's Little Black Book" quoted her as saying: "Hef's the easiest man in the world to please, provided everything is done just the way he wants it."
The book also contains a copy of a memo O'Connor had sent Playboy Executive Vice President Richard Rosenzweig on June 28, 1972, in which she lists several items that she says were damaged by members of the Rolling Stones during an overnight stay at the Playboy Mansion.
Among them -- a burnt toilet seat, several stained bedspreads as well as a chair and a couch and razor blades that were dropped down a sink, which blocked up the pipes.
Check out a video clip of Mary O'Connor in an episode of "The Girls Next Door" below.