They've both been going through a lot of changes in their lives, and both Kate (Chrissy Metz) and Kevin's (Justin Hartley) relationships and love stories are also going to see more upheaval on This Is Us. 

In an interview with Us Weekly, Hartley revealed that neither his character or his on-screen twin sister are set to have entirely easy paths ahead, as their stories will still have some major hurdles to clear.

For Kevin, Hartley teased, his problem concerning the recently returned Olivia (Janet Montgomery) and his burgeoning romance with Sloane (Milana Vayntrub), isn't likely to be resolved anytime soon, despite his telling Olivia that he was committed to continue working with Sloane and that she couldn't suddenly come back and expect him to drop everything for her. And even more, he says fans will be surprised by how the story will play out.

"Everybody will be really surprised, and I think people are going to be really invested in it because it's not something that you see coming. It's an a-ha moment, and it explains a lot about why Kevin is how he is, and it's heartbreaking a little bit as well. Actually, massively heartbreaking!"

"There's a huge payoff," he added. "It's a big buildup, and [viewers will wonder]. 'Wait, where is his love going?' And he's just kind of lost. And he's got these two girls, and he's trying to figure it out-it's just a really unique situation. Also, I've never been in that situation where you're like, 'Which girl am I going to pick?' Most guys don't have that situation, right? But for him, it's just another Wednesday, I guess. But he figures it out, and he gets a little advice."

He also admitted that Kate and Toby's (Chris Sullivan) romance will also still face a few bumps in the road, despite the pair being in a seemingly better place now after Toby's health scare.

"Everything is always in flux [for them], which makes for good storytelling," he said. "She loves him, and he loves her, and you'll see a lot of that, but it's not always going to be smooth sailing, just as in every relationship."

This Is Us airs Tuesdays at 9 p.m. on NBC.

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