An all-new “Sister Wives” Season 6 episode is hitting TLC this Sunday evening, and fans of the reality show who are feeling that it’s being taken over by Robyn Brown will finally get to see the other wives and their issues with the family and polygamist patriarch Kody Brown.

Ahead of the show's upcoming episode, teaser clips were released via YouTube and the series' official TLC page. One of the sneak peeks features Kody and wife Christine hiking in Utah. When they were treading uphill and began to struggle catching their breaths, Christine reveals to Kody, "I've been thinking about going back to a trainer."

In a voiceover, Christine admits that her weight has always been an issue. She then adds, "There's been a lot of factors over the years...that have kind of contributed to the weight gain."

The "Sister Wives" star then says that she's thinking of shedding some weight because "I am important now. I am able to take some time for me." She then recognizes her husband whom she said never made her "less beautiful."

Christine Brown's announcement of her desire to lose weight comes amid Robyn's pregnancy. The latter is due to give birth to another Brown clan member on Jan. 7, 2016, as per International Business Times.

While Robyn is due to give birth to her second child with Kody, her kids from a previous relationship have played a pivotal role in the "Sister Wives" Season 6. In one of the early episodes, the family's lawyer revealed that Kody now has the chance of adopting Robyn's children after the two of them legally tied the knot in Dec. 2014, after Meri Brown agreed to it.

Meanwhile, in this week's episode, show fans will get to see the aftermath of Kody and Christine's issue when they engaged in a Galveston, Texas anniversary trip last week.

In the episode, the couple was by the shore when their marriage counselor suggested that they build a rock sculpture to show how well they are as husband-and-wife in their relationship, reported Inquisitr.

However, instead of focusing on just Christine, Kody made it a family affair and used four rocks at the base to signify his four wives. "Well, foundation of four rocks, my four wives," Kody said.

But to Kody's words, Christine felt she was being shortchanged saying, "I can see that Kody was building a tower that represents the family and doesn't represent our relationship... Could it be a little different? Maybe this time...can we have it just about us this time?"

Kody said that Christine should just trust him, and the latter gave an "Okay" while smiling a little. And in her solo-cam, Christine once again brought up the issue saying: "I'm like oh my gosh! Can you just be present? Can you just be here...with me? He just doesn't get it."

Don't miss the all-new episode of "Sister Wives" Season 6 this Sunday night. Tune in on TLC at 9 p.m. EDT.