Martha Stewart shared a bombshell secret about her 26-year marriage to ex-husband Andrew Stewart. RadarOnline.com can reveal the domestic diva confessed to having an affair while she was still married, but blasted men who had “flings”. Stewart, 83, didn’t hold back as she scolded men who cheated on their wives as “piece(s) of s—“. The 83-year-old revealed her secret affair in the trailer for the upcoming Netflix documentary on her life and domestic empire, Martha, which is set to hit the streaming platform on October 30. With her blonde hair neatly styled, Stewart dolled out marriage advice …