Kody Brown opens up about Robyn Brown's reaction to his splits from his first three wives - and why he worries about their future - on the new episode of Sister Wives. "Robyn struggled with the whole thing," Kody, 56, confesses about how Robyn, 47, feels becoming his only wife during Us Weekly's exclusive first look at the Sunday, October 19, episode of the TLC series. He notes, "She married me under the premise of plural marriage with the expectation of plural marriage." Kody admits, "When the other wives left, I wondered if my value to her was diminished. I'm still wondering." TLC/YouTube Kody married Meri Brown in 1990 before entering into spiritual unions with Janelle Brown and Christine Brown in 1993 and 1994, respectively. He spiritually wed Robyn in 2010 before legally divorcing Meri four years later and marrying Robyn. At the time, Kody also legally adopted Robyn's three children from a previous marriage. Less than a decade later, the Brown family fell apart. Christine, 53, announced her split from Kody in November 2021 and Janelle, 56, followed in December 2022. Meri, 54, confirmed her separation from Kody in January 2023, leaving Robyn in a monogamous relationship - but not by choice. 'Sister Wives' Preview: Kody Asks Robyn to 'Accept' Him as a Monogamist "Sure, being the only wife is great in some ways, but there's also ways that it's not great," Robyn says in the exclusive preview. "This was not the life that I expected and not the life that I planned for myself." Robyn confesses, "While I love Kody, I did not ever intend or expect or want to have him to myself. I always wanted to live plural marriage. I wanted to live my religion." 'Sister Wives' Star Kody Admits He's Afraid Robyn Will Get Hit On at Church "We made our covenant on the basis of having the other wives," Kody tells his brother in the clip, hinting that it hasn't been what Robyn signed up for at all. His brother then recalls, "I remember growing up, you were the coolest polygamist I knew. Right? Then now you're not." TLC/YouTube Kody admits, "It's not a polygamist at all, you know." Elsewhere in the preview, Kody tells his brother how his failed marriages inspired his and Robyn's choice to sell their family home in Flagstaff, Arizona, and find a new one close by. Kody Brown Claims He's 'Never Been Allowed' to 'Be in Love' With Robyn "Robyn and I have lived in Flagstaff for six years. Five of those years have been in this house," Kody says. "These five years have been the five years that my family has just eroded, crumbled and moved on." An emotional Kody then tells the cameras, "You haven't seen jack for what happened. It was [a] very, very painful experience." He later tells his brother in the kitchen while packing, "There was such a want to change my environment. That's just from pain. That's just something to do with trauma, emotional trauma." Sister Wives season 20 airs on TLC Sundays at 10 p.m. ET.