 Later , Kody and Meri go to Mexico to celebrate their twentieth wedding anniversary , where Meri discussed her sadness about her infertility problems and the jealousy that has arisen from Kody 's engagement to Robyn . Kody proposes in vitro fertilisation , but she turns down the idea as she is only interested in a naturally occurring conception . As Robyn 's wedding approaches , the three sister wives help Robyn prepare , and they begin to bond . However , Kody upsets his wives when he reveals he secretly chose Robyn 's wedding dress himself , which makes Christine feel so betrayed that she angrily walks away in mid @-@ interview . Kody eventually apologizes , and the five reconcile . The first season finale ends with the wedding of Kody and Robyn , where Meri , Janelle , and Christine present her with a <unk> ring to welcome her into the family . 
