"Oh my god," groaned Olivia Pierson during Sunday's new Relatively Nat & Liv. Minutes earlier, the Instagram personality's little sister Sophia Pierson tried inviting herself to London—where she and Natalie Halcro were headed for a work meeting with U.K. brand Comino Couture—for the first of several times throughout this week's episode.
"Like, you're f--king kidding me," Nat said in a confessional.
"Surprise, surprise," Liv chimed in.
The fashion designers, cousins and longtime BFFs didn't do much to hide their distaste for Sophia's travel request in the moment, either. Nat and Liv pretty much told her "no" flat-out, so it wasn't a surprise to see the youngest Pierson sibling develop some hurt feelings after their exchange.
"I heard a few little things about you and 'Phia," Liv's dad Brian Pierson told her during an afternoon stroll by the waterfront.
"Let me guess," his oldest daughter shot back. "She's mad about London."
It turned out Sophia wasn't so much mad as she was plain old sad about not having been invited on the trip—and not having been welcomed by her sis and cousin once she'd made it clear she wanted to go—especially since she's felt excluded from Nat and Liv's personal and professional ventures before.
"You know, 'Phia's a little bit sensitive about you and Natalie," Brian reasoned, noting that as she and Nat grew up and got closer, Sophia "got just sort of naturally pushed aside."
This time around though, the Pierson father was keen to make sure both daughters' voices were heard. After chatting alone for a bit, Brian told Liv her sister was on her way over to meet them too.
"Smooth move," she sighed. But when Sophia sat down on the bench beside them and started to cry, Liv rejiggered her attitude and approach to the whole situation.
"I'm sorry," she told Sophia. "I can't imagine what it would feel like to be the younger sister of like…me and Nat. That probably would be hard."
"I don't know, I just feel like I don't have my sister as much," said Sophia, who was obviously still really upset. "I just want us to hang out more."
Of course, her older sis agreed that "Yeah, we can hang out. For sure." (Again, dad was literally sitting between them referee style at this point.) So, London then?
"Ugh! Oh my god," Liv repeat-whined in another confessional. "I'm screwed, aren't I? I have to let her come. After talking to dad, I have to let her come. Yup."
"I really do want to come to London," Sophia reiterated later, in the midst of shopping with her sister and Nat before their big trip. "Would you be OK with that?"
Liv's face said "please no" but—in a move that probably resonated with older siblings everywhere—she managed to actually say, "Yeah," and then, "I don't care." Because this is still a work thing and she's not going to beg her, OK!
"I know it's a work trip obviously," Sophia acknowledged. "But could you just be a little more excited? 'Cause I feel like a big loser."
"You want to come?" Nat tried. And obviously her cousin replied in the enthusiastic affirmative.
The London drama didn't quite end there, though. Catch Liv and Sophia's final confrontation this week—plus, find out what went down when the set-up tables turned and Brian found himself at a solo dinner with ex Julia Pierson—in the full recap video above!