Martha Stewart can keep a secret. 

The home and garden guru revealed this week it was "very easy" to keep confidential the decades-old affair she recently revealed.

"You have to be circumspect," the 83-year-old told businessman Lee Brian Schrager while celebrating her 100th book Wednesday night. Schrager had asked how she kept the affair a secret all these years, joking it could be the subject of her next book.

Video of the exchange was posted by the Daily Mail

MARTHA STEWART SAYS INA GARTEN STOPPED TALKING TO HER AFTER STEWART WENT TO PRISON 

Martha Stewart with her ex Andy Stewart

Martha Stewart said this week it was "very easy" to keep her affair a secret.  (Arthur Schatz/Getty Images)

Earlier this month, in the trailer for her new Netflix documentary, Stewart admitted she had an affair while married to her only husband, Andrew Stewart. Their marriage lasted from 1961 to 1990. 

"Young women, listen to my advice, if you’re married and your husband starts to cheat on you, he’s a piece of s---," Stewart said in the trailer. "Get out of that marriage." 

When a producer asked, "Didn’t you have an affair early on?" she answered, "Yeah, but I don’t think Andy ever knew about that." 

The new documentary covers Stewart’s marriage, her rise in the lifestyle industry and her legal woes

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Martha Stewart with her husband

Martha Stewart was married to Andrew Stewart from 1961 until 1990.  (Arthur Schatz/Getty Images)

"What does it mean to be the first female self-made billionaire in history?" Stewart asks herself rhetorically at the beginning of the trailer before laughing. 

She added in the trailer she was "considered crazy" as her career came together, "but it worked." 

Martha Stewart with Snoop Dogg

Snoop Dogg supported Stewart at the launch of her new book Wednesday night.  (Snoop Dogg/Instagram)

Stewart, a former model, worked as a stockbroker and then began a catering business in the 1970s that led to her first cookbook, "Entertaining," in 1982. More cookbooks followed, and she began to make TV appearances. 

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Her magazine, Martha Stewart Living, published its first issue in the winter of 1990. 

Martha Stewart with Lee Schrager

Lee Schrager, right, asked Martha Stewart Wednesday night how she kept her affair a secret all these years.  (Astrid Stawiarz/Getty Images for NYCWFF)

Stewart's bestie, Snoop Dogg, was also at her book launch Wednesday to support her. 

Martha Stewart at her book launch

Martha Stewart celebrated the launch of her 100th book Wednesday.  (Astrid Stawiarz/Getty Images for NYCWFF)

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"Had 2 come out n support @marthastewart48 n NYC !!! Anotha book release 4 the ppl. We appreciate U," he wrote on his Instagram along with a photo of him posing with her and holding her new book.