Polygamist Kody Brown faces tension among his four wives, as multiple changes in the family continue in "Sister Wives" Season 6.

In the 9 p.m. episode on Sunday, "Marriage Counseling Texas Style," Brown takes wife Christine Brown on an anniversary trip to Galveston, Texas, where she reveals to him that she believes he gives new wife Robyn more attention. The anniversary trip turns into couple's therapy, as Kody tries to cope with Christine's feelings of detachment for the first time.

In a video clip of the episode, Christine reveals her feelings during a confessional.

"I don't think Kody is very equal with his time," Christine says. "I think he caters to Robyn, to Robyn's needs, to Robyn's kids, to whatever Robyn needs. I think that he is spending all of his time building up his and Robyn's relationship."

She says that Kody doesn't realize their relationship isn't "that great," and he needs to spend some time developing their relationship, too.

In the clip, Kody says that he's never known Christine to be so troubled in their relationship.

"I've loved her all my life. We've had a great relationship. We're just at a point where we need to work through some kinks," he says.

Kody and Christine have been spiritually married since April 1972.

In the same episode, before the Brown family leaves for Texas, they meet with their lawyer to start the process of adopting Robyn's three children.

The description of the 10 p.m. episode "All About Christine" on TLC reads, "[Christine] reveals the things she never wanted to talk about at all and what she was really thinking during the most memorable moments of the past five years."

Watch "Sister Wives" episodes "Marriage Counseling Texas Style" at 9 p.m. EDT and "All About Christine" at 10 p.m. EDT Sunday, Sept. 27 on TLC.

Do you believe that Kody is neglecting his other wives in favor of Robyn? If so, do you think that's natural considering they are newlyweds and he's adopting her children? Share your thoughts in the comment section below.