Kody Brown is facing an unexpected challenge in his marriage to Robyn Brown: adjusting to life as a monogamist after years in a plural marriage

The Sister Wives star opened up about the challenges of navigating a monogamous marriage with Robyn after his separations from Christine Brown, Janelle Brown and Meri Brown.

“There’s this strange thing that Robyn and I were in plural marriage together,” Kody explained during the Season 20 premiere on September 28. “It all came together and then they all just left. Like we’re monogamous, but we didn’t choose that.”

He added, “I’m now in a different marriage than I’ve ever been in.”

Even Robyn, who shares two of Kody’s 19 children, admitted she isn’t used to having him around so much. “It’s definitely a different balance,” she said in her own confessional. “He wasn’t there all the time. It was a couple times a week. I think because he had so many wives, he didn’t have to check in the same way as you would as a monogamist.”

Robyn also revealed to Kody that monogamy isn’t something she has traditionally wanted. She shared that she’s turned down past partners who weren’t interested in a polygamous lifestyle.

“If there was somebody who was really supportive and really wanted to work and really wanted a relationship with me as well as with you, not just you,” she explained to Kody during the episode, “And then we had a guarantee that it was going to be OK and it was going to be wonderful and it was going to be what I always dreamed it was supposed to be, that would be something to really, truly consider.”

Despite this, Kody admitted that the only reason he would consider opening up their marriage again was sexual attraction. “My primary motivation, I’m afraid, at this state in my life, would be how good looking she is,” he told Robyn, who burst out laughing. “I’m not kidding.”

Robyn playfully called him out, saying, “You don’t understand how you’re coming across.” In a later confessional, she added, “You’re just kind of being a pig right now.”

The couple ultimately agreed that adding another person to their marriage wasn’t feasible at this time, but Robyn made it clear how off-putting she found Kody’s reasoning. “For me, I’m like, OK, so you have the real relationship with me,” she explained in a confessional. “But then she’s just like, what? A concubine? ‘Cause that’s pretty much what that is.” She continued, “It should be more than that for sure.”