TLC's Sister Wives is in its third season, and the series about polygamists Meri Brown, 39, Janelle Brown, 40, Christine Brown, 37, and Robyn Brown, 31 — all of whom are married to patriarch Kody Brown, 43, who has 17 children among them all — has always cultivated its share of controversy and fan speculation. Now the "sisters" and wives are opening up about what it's really like to live their alternative polygamist lifestyle and their new tell-all book, Becoming Sister Wives.

"That's okay if Kody chooses a fifth wife," was one of the most shocking revelations, voiced by most recent wife Robyn, on Sunday night's NBC special on the series, according to Hollywood Life. "I signed on for that." Meanwhile, newbie Robyn's endorsement wasn't backed up by Meri, Janelle, or Christine.

It turns out that Meri and Janelle, Kody's first and second wives, have experienced the most historical strife. Meri's fertilitiy issues and Janelle's quick pregnancy was the foremost issue that rocked their relationship years ago. "If it upset her, so be it," Janelle said she felt about her pregnancy at the time. "Things had been incredibly uncomfortable at that time so her feelings were of little importance to me." Among the "things" that made Janelle feel she was "on the verge of a nervous breakdown" was Meri's incessant badgering about the makeup sister-wife Janelle would wear.

Third wife Christine admitted that she was "very mean" to her sister wives when she got pregnant. "I hope you don't get pregnant," she told Meri. "Because then it won't be such a special thing for me."

Watch Kody talk about his spirituality in the following video, via Hollywood Life:

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