Robyn says that her marriage to Kody has suffered in the wake of his splits from his other wives.
The truth came out during part 2 of the tense 'One-on-One' special with Sukanya Krishnan.
The exes claim Robyn tried to insert herself into their marriages with Kody Brown.
The Brown family patriarch says he did not feel 'safe' with his now-ex.
The TLC show is currently airing its 'One-on-One' special recapping the season.
On the 'Sister Wives’ one-on-one special, Kody claims that he was never in love before he met and married Robyn in 2010.
Robyn was Kody Brown's fourth wife and has since become his only remaining spouse.
Robyn is the only remaining wife married to the former polygamist.
On 'Sister Wives,' Robyn breaks down in tears as Meri tells Kody she's moving away and agrees their relationship is over.
Kody did not appreciate his only remaining wife's joke at his expense during Sunday's finale episode.
Kody and Robyn have the majority of the shares of the property and they are the only ones still in an active relationship.
In ET's clip, Meri puts up a fight when Kody brings up unevenly dividing the family's land. 'Sister Wives' airs Sundays on TLC.
Kody is estranged from many of his older children, whom he shares with exes Christine and Janelle Brown.
Kody is starting to see that he no longer fits into Janelle's world on this week's episode.
