Kody Brown said he was "dumbfounded" when his third wife, Christine, kicked him out of her bedroom.
He had previously told her that he wanted to have a "romance-free" marriage.
"I'm not interested in a half-marriage," Christine said on Sunday's episode.
Fans got a candid look at the dissolution of "Sister Wives" stars Kody and Christine Brown's relationship on the season sixteen finale, titled "The Beginning of the End."
Christine, the third of Kody's four wives, "spiritually" married the polygamist patriarch, who is only legally married to fourth wife Robin, in 1994. She announced she had left Kody in November 2021 via Instagram. The two were still in a relationship throughout filming of the currently airing season, which appeared to take place in 2020 and early 2021.
But cracks in the relationship were visible throughout season 16, and things appeared to come to a head in the finale.
On Sunday's episode, in a self-taped video confessional presumably filmed in early 2021, the father of 18 recalled that he was "dumbfounded" when Christine, the mother of six of his kids, told him she didn't want him to stay in her bedroom anymore.
"She's like, 'My room is a special place for me and nothing special happens there for us," he said in the confessional. He added that he'd told her he knew a lot of people in "romance-free" marriages, but Christine refused to entertain that idea for herself.
In the Brown family, each wife maintains a separate residence with their own kids and Kody typically rotates between them.
Kody was skeptical of Christine's wishes at first, wondering whether this was a "phase" or "an awakening."
In a separate sit-down interview on Sunday's episode, he explained how he wanted a romance-free marriage with Christine because she'd "murdered" their intimacy with "betrayal" because, according to Kody, Christine had been telling his other wives and adult children that she's wanted to leave him "for years."
"I don't feel intimate because I've been betrayed," he said, adding that though he was "shocked" he "shouldn't be surprised," given how long their marriage has been troubled.
Christine separately opened up about not wanting 'a half marriage'
In a solo confessional, Christine talked about how Kody's decision not to have an "intimate" marriage with her anymore influenced her decision to remove him from her bedroom.
"So, he gets to have an intimate marriage with other wives but not with me?" she asked the camera. "And I'm, what? Gonna have nothing for the rest of my life?"
"My heart's shattered to be honest with you," Christine continued, adding that she's "not interested in a half marriage or a partial marriage or whatever we have."
In a self-taped confessional on Sunday's episode, Christine explained how she decided to pack up the stuff Kody kept in her room and put it in the garage so that he wouldn't have to pack it up himself when visiting their daughters at her house.
"It is so heartbreaking to have his stuff everywhere. And to know that he doesn't want me, he doesn't love me," Christine said.
For Christine, the end of their marriage was a long time coming but still full of sadness. She said that their last anniversary made her so sad that she promised herself she "wouldn't have another anniversary" with Kody and that she wants to move away from the community where Kody and her fellow "Sister Wives" all live: "I want to go somewhere where people want to be around us."
As for Kody, this apparent final break in his relationship with Christine didn't really upset him. According to the reality star, when he found his stuff in Christine's garage he said he wasn't bothered but rather felt "relief" from "the burden" of a "loveless marriage."
The "Sister Wives" season 16 tell-all episode will air Sunday at 10 p.m. on TLC.