It's a dramatic change for the Brown family, chronicled on the special, 'Sister Wives in the City of Sin' (Sun., 9PM ET on TLC). But uprooting the entire family and relocating them to Utah turned out to be only the first big change on the horizon for the clan.

Fourth wife Robyn is harboring a secret, alongside Kody, from the rest of the family. "We have a bun in the oven," Kody revealed. "We're expecting a baby in October."

Neither has revealed this news to anyone in the family just yet, though they realize they'll need to. It seems that Robyn is a little concerned about how the bombshell will be received by the family.