Extreme Sisters : 2 Adult Siblings Continue to Sleep in the Same Bed in New TLC Series

It may be common for sisters to have a close bond, but Extreme Sisters' Brooke and Baylee are taking it to another level.

On Sunday, TLC audiences will be introduced to the inseparable siblings, who continue to shower together, pop each other's pimples and even share the same first name, Candace-Brooke and Candace-Baylee — a tradition that Brooke has passed down to her daughter, Candace-Ace.

Now that they're adults, and 24-year-old Brooke is married, the sisters are having trouble letting go of an old habit: sharing a bed together.

"While Baylee's been living with us, she's been sleeping with Ace in her room," Brooke says in a PEOPLE exclusive sneak peek, as younger sister Baylee, 22, chimes in, "and then with you in your room."

TLC Extreme Sisters' Brooke and Baylee

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"When we were kids, no matter where we stayed, Baylee and I always shared a bed," Brooke explains. "That was just kind of our safe space with each other."

In the footage, Brooke's husband, Denver, confronts the duo about the fact that Baylee — who is living with the couple in Oklahoma — has slept in his and his wife's bed "three out of the last four nights."

Later, the clip cuts to the three lying in the same bed, with Baylee hiding underneath the covers in between Brooke and Denver.

Though Brooke tells her younger sister she has to leave before Denver wakes up, he's already awake — and he isn't exactly thrilled that Baylee has joined them.

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TLC Extreme Sisters

"Maybe instead of me being in the middle, you should be in the middle," Baylee suggests during the confrontation.

"That's not the point," says Denver. "That's not the resolution."

Brooke tells him: "Alright, we'll talk about it."

Extreme Sisters' Brooke and Baylee

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While Brooke realizes she needs to "detach" from her little sister, Baylee is also having a hard time letting go.

"Being married now, I realize that I need to detach from my sister a little bit, but it's so hard, it really is. 'Cause she's my best friend," Brooke says during a confessional, as Baylee admits: "I'm not really trying that hard to detach."

Extreme Sisters premieres Sunday at 10 p.m. ET on TLC.