'Welcome to Plathville' : Moriah Chooses Sister-in-Law Olivia Over Parents to Attend Her Concert

"My boundary for Moriah's gig is that I would love to play with her, but I'm not ready to do that if I have to see her parents there," Olivia Plath says about her in-laws

When it comes to her estranged in-laws, Olivia Plath wants to maintain boundaries.

On Tuesday's upcoming episode of Welcome to Plathville, Moriah Plath asks her sister-in-law to be in her band and play at her first gig with her. But while Olivia, 23, wants to support Moriah, 19, she doesn't feel comfortable knowing that her husband Ethan Plath's parents, Kim and Barry Plath, could also be at the show.

"Boundaries are really messy things, especially when it comes to family," Olivia says in a confessional. "And my boundary for Moriah's gig is that I would love to play with her, but I'm not ready to do that if I have to see her parents there."

"It's a really hard thing to say to Moriah, because it does put her in the middle where she has to make a choice," she adds.

While hanging out with her sister-in-law, Olivia asks about Kim and Barry's possible attendance.

Olivia Plath.

"I feel weird asking this, but if you don't mind me asking, are your parents going to be there?" she says.

"I mean, I haven't really thought of that," Moriah responds. "I think that maybe. I dunno, like, I wish my little sisters could be there and Ethan can come."

While Olivia doesn't want to put Moriah "in a weird place," she is frank about not wanting to see Kim, 48, and Barry, 53, with whom she and Ethan, 22, no longer have any contact.

"To be completely honest, I really don't want to see your parents. Like, I don't feel like I'm at a place where I've healed enough to see them," she admits. "But I'm not going to be like, 'Oh Moriah, I'll play with you, but that means your parents can't be there.'"

She then suggests that Moriah's brother Micah "could totally [be in the band instead]" if Moriah did want her parents there. With it being her first show, Moriah wants it to go off without a hitch — and voices her preference for Olivia to be there over her parents, who could attend future performances.

Moriah Plath.

"It's my first concert. I just want it to be like, okay, I'm going to get through it and the whole world doesn't have to see it. Like, my parents don't have to be there. I know there'll be a bunch in the future where like, there'll be more opportunities," she says to cameras.

"I kind of really want you in the band," Moriah tells Olivia.

"I'm happy to do it," says Olivia, who notes they'll need some practice before the big day. "I just want to make sure you don't feel like you're obligated to have me there instead of them."

Welcome to Plathville's Plath family. TLC

"My parents will just have to understand, 'cause I can't just go around being scared of what everybody else is going to feel like or be offended or hurt or whatever," says Moriah.

And while Moriah would ideally like her "whole family at this concert," she recognizes that Olivia is "super organized [and] brings a lot of structure," adding that Olivia would "help pull this together."

"I just feel like it'll be better," she says. "Especially for a first concert, I kind of need that."

Welcome to Plathville airs Tuesdays (10 p.m. ET) on TLC.