Martha Stewart's Ex, His Wife Share Statement About 'Abusive' Marriage to Star

Martha Stewart's ex-husband and his wife are speaking out ... saying he was in an "abusive" relationship with the businesswoman -- this, after Martha admitted to cheating on him.

Shyla Nelson Stewart -- wife of Andrew Stewart, who was married to Martha from 1961 to 1990 -- released a statement on Facebook before the documentary "Martha" dropped on Netflix ... saying she and Andrew have been in a loving relationship for more than a decade.

Shyla says she and her husband enjoy a happy blended family life ... with their kids from their previous relationships and grandkids bringing them immense joy.

However, Shyla says Andrew's life wasn't always this way ... admitting he had dark chapters in his life "including a painful and abusive marriage to Martha."

While Andrew's moved on, Shyla says she claims Martha clearly hasn't ... 'cause she's choosing to publicly air their dirty laundry again almost 35 years after finalizing their divorce.

Shyla and Andrew -- who cosigned the Facebook post -- seem to throw a little shade at the end of the post ... adding they "wish everyone, including Martha herself, the experience of loving and being loved deeply and fully, and the peace that comes from such a love."

As we told you ... Martha made headlines last month when she said in a teaser for "Martha" that women should leave their husbands if they cheat -- only for someone on set to remind her she cheated on Andrew.

She replied, "Yeah, but I don’t think Andy ever knew about that" ... so, unclear exactly what her moral line is when it comes to stepping out on a spouse. Martha and Andrew share one child ... a daughter named Alexis, who was born in 1965.