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 have arisen from Kody 's engagement to Robyn . Kody propose in vitro fertilisation , but she turn 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 upset his wives when he reveal he secretly chose Robyn 's wedding dress himself , which make Christine feel so betrayed that she angrily walk away in mid @-@ interview . Kody eventually apologize , 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 Claddagh ring to welcome her into the family .