A new clip from the show in which all the family members discuss the just-concluded season reveals that Kody, 49, and Meri, 47, don't pull any punches about their troubled relationship.
Meri is Kody's first wife and only that marriage, and his fourth one, to Robyn, were legal.
Kody divorced Meri in 2014 to wed Robyn legally. The family also includes two other "wives," Christine and Janelle.
The host of Sunday's special, NBC's Andrea Canning, re-lives the Sister Wives controversial scene this season in which Kody was in the car on speakerphone with a reporter and said that Meri claims to be his wife, but they don't live together.
Canning grilled Kody, asking, "Why did you feel that was important to share?"
"I was feeling a little snarky. Not towards Meri, but towards this law," he replied, referring to the his bizarre family situation in which he has claimed four "wives" – but that isn't legally recognized.
Canning then asked Meri how she felt about Kody's comments, and the sister wife replied, "What's hard to hear is you saying that you feel like a divorced couple living on the same block and the lack of intimacy."
Canning asked Kody, "And you saying that you don't want to be intimate with Meri right now. Is that still where things stand?"
"Yes," he confirmed.
Then Meri, who opened up a bed and breakfast on her own, shared, "I want more of a relationship with him than we're having right now."
As RadarOnline.com reported, Meri recently sent out a cryptic tweet about not being good enough.
Back then, she posted on Twitter, with the message all in caps for emphasis, "THERE COMES A POINT WHEN YOU HAVE TO REALIZE THAT YOU'LL NEVER BE GOOD ENOUGH FOR SOME PEOPLE. THE QUESTION IS, IS THAT YOUR PROBLEM OR THEIRS?"
Meri didn't explain what she meant.
Meri had previously stunned fans by admitting she'd gotten scammed into a humiliating catfishing scandal with a woman online.
In the new Tell All show preview clip, though, Meri seems to still want to fix her relationship with Kody, saying it will take "two parties wanting to work toward it, I think. I think it's a lot of work."
Sister Wives airs Sundays at 8 p.m. ET on TLC.
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