Despite their ups and downs, Kody and Robyn Brown seem to be in it for the long haul.

The longtime reality-TV couple, who star on the TLC series “Sister Wives,” got candid on navigating their rocky marriage during the Sunday, Jan. 4, episode.

“Sister Wives,” which has been on the air since September 2010, chronicles the at-times complicated lives of Kody Brown’s polygamist family, which includes his yearslong marriage to Robyn Brown and his former marriages to Meri Barber, Janelle Schriever and Christine Brown Woolley. The family shares 18 children between the four couples.

Kody and Robyn Brown were legally married in 2014 after meeting in 2009. Meanwhile, Kody Brown’s “spiritual marriages” to Barber, Schriever and Brown Woolley each ended in recent years, with Kody and Barber’s 2023 split being the most recent.

“Robyn and I are fighting for our marriage and our life together,” Kody Brown said on Sunday’s episode, acknowledging the emotional toll that his “spiritual” divorces from his previous wives have taken on the pair’s relationship.

“We have been going through four years or more of breakup with the family,” Kody continued. “I guess what I’m saying is Robyn and I have a great relationship when I’m being me, when I’m being brave and kind.”

Kody Brown, who made amends with his former spouses, went on to give an emotional apology to Robyn Brown for “all of my BS, all of my weakness, all of my anger, all of my ranting and raving and complaining.”

“I haven’t been very fair with you,” Kody Brown told Robyn. “In spite of all how brutal they were, I was apologizing to them. But you were never brutal. You’re never unkind. You’re never disloyal. I’ve been apologizing to everybody. I think I owe you an apology most of all.”

For her part, Robyn Brown shared her appreciation for Kody Brown’s marital mea culpa.

“Taking accountability for his part in the marriages falling apart was something that gave him some peace, and it’ll help in his healing,” Robyn Brown reflected. “But then I also just see him just kind of taking a sigh of relief. Just like, ‘OK, I took accountability for my part.'”

Robyn Brown’s ‘sister wife’ Christine Brown Woolley details tumultuous Kody Brown marriage

Kody and Robyn Brown aren’t the only ones getting real on the difficulties of polygamist marriage.

Brown Woolley, who broke up with Kody Brown in 2021, detailed the former couple’s tumultuous marriage in her memoir “Sister Wife: A Memoir of Faith, Family, and Finding Freedom,” which was released in September.

The reality-TV personality revealed her relationship with Kody Brown strained over the years, as his attention to her and their six kids waned, especially after he married his fourth wife, Robyn Brown. She said she “never felt secure” in their relationship.

Brown Woolley also accused her ex of withholding quality time with her, comparing her behavior to that of the other sister wives and “love bombing” gestures when the women pulled away from Kody Brown.

“If I complained about our marriage on the show, Kody spent less time with me and my kids,” Brown Woolley wrote. “If we didn’t do things his way, he’d punish us by withholding his attention. … Husbands don’t go to the doghouse in polygamy. They go to the next wife in the chain.”

As for raising their blended family, Brown Woolley claimed Kody Brown was largely absent as a parent, telling her to lean on the other women for child care instead of asking him for help.

Brown Woolley said a breaking point in their relationship came when their daughter needed spinal surgery and Kody refused to travel with them.

Contributing: Clare Mulroy, USA TODAY