At the beginning, the Brown family went into Sister Wives with the intention of showing that plural marriage was marriage like any other.

They weren't wrong: a plural marriage can be every bit as messy and painful as a monogamous one.

Even Kody admits that his wives have never been true equals. He knows it, they know it.

It's not just that Janelle and Robyn don't like each other. They've never been friends.

At first, as the Sister Wives stars bared their souls on the finale, the focus was all on Christine and Meri.

Meri had stuck with Kody the longest and endured a decade of celibacy. Christine had felt like a Basement Wife.

But as the finale special continued, it became clear that things weren't good with Janelle, either.

On Part 2 of the finale special, Kody admitted that Janelle and Christine don't care for Robyn.

While Christine has bigger fish to fry when it comes to consciously uncoupling from Kody, Janelle is still Kody's wife.

As such, she and Robyn cannot ignore their owngoing tension.

That doesn't mean that they want to mend it.

Specifically, Janelle admitted on camera that she is unsure of whether she even wants to mend things with Robyn.

That is clearly one of several sticking points for Kody, who considers trying to get along part of his expectations for his wives.

Kody seemed downright angry that Robyn doesn't have closer ties with the others.

He clearly doesn't blame Robyn, either.

“Frankly, other than Meri, I’m not sure the others would ever want to be [Robyn’s] friend,” Kody admitted.

Kody described what he saw as a "pecking order" among his wives.

Essentially, each new wife got the cold shoulder from the previous ones, but then joined in doing it to the next one.

Robyn is at the end of the list -- so, like someone at the bottom of a pyramid scheme, her situation just plain sucks.

Robyn has characterized her position as the "Brown Family Scapegoat" more than once in the past.

She has shared that she's tried to mend things with Janelle.

Janelle, however, has turned her down.

“I had a conversation with Janelle recently where I said, ‘Hey, let’s figure this out. I want the good sister wife relationship. I know they exist,'” Robyn described.

She recalled: “And she kind of said, ‘Well, you know, I’ll have to think about that.'”

That might sound harsh, but it wasn't so different from Janelle's description of that same exchange.

“There is some history there, in the past, that…I mean, my desire [to get along with Robyn] is there." Janelle stated.

"But," she admitted, "I’m kind of like, ‘Ugh, do I want to do this again?'”

Janelle explained her lukewarm response: “I felt like I was kind of being put on the spot. And I’m like, ‘I don’t know. I don’t know.'"

In slight contrast, Christine said that she never deliberately moved to exclude Robyn or Robyn's kids from anything.

Yes, she acknowledged, there was resentment and some emotional scarring from the way that Robyn joined the family.

Arguably, it's not really Christine's problem anymore. But Janelle and Robyn may have to find a way to deal with this.