EXCLUSIVE: 'This Is Us' Stars Reveal the Swoon-Worthy Secrets to Their Onscreen Chemistry: 'He's My Other Half

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The stars of This Is Us can't get enough of each other!

"At this point, it's like he's my other half," star Mandy Moore gushed of her This Is Us husband, co-star Milo Ventimiglia. "I saw him this morning and I was like, 'I haven't seen you in three or four days. I miss you!' He's like, 'I know. I miss you, too!'"

ET caught up with the entire This Is Us cast earlier this week at NBC’s Television Critics Association press tour and discovered the swoon-worthy secrets to their onscreen chemistry.

"[Mandy] is one of my good friends now," Ventimiglia spilled to our camera. "And, hopefully, I'm one of her good friends. That's the thing -- when I have good friends, I'm always going to look out for them, protect them, make sure that they feel safe, especially someone that I'm acting with, and playing my wife, you know? It's like I want her to do the best work she can possibly do, just like, you know, she's supporting me. So, I give her everything I can."

Be honest: who else is swooning so hard right now?

EXCLUSIVE: 'This Is Us' Star Milo Ventimiglia Reveals Big Jack-Rebecca-Miguel Clue

Meanwhile, Susan Kelechi Watson confessed that she and Sterling K. Brown discovered an emotional shortcut find Beth and Randal's enviable onscreen closeness as husband and wife.

"He and I would tell each other secrets that nobody else knows and he did that as a sort of exercise in trust between us," Watson shared with a smile. "It was like a game that we started doing. We realized we're OK. Our dynamic as friends off-camera just became fuller and fuller as it went on. He and I studied together at NYU, and we come from the same theater background and training. We just really trust each other. We have a good time."

"I am very blessed," said Brown, referencing the fact that his This Is Us wife and his offscreen wife, Ryan Michelle Bathe, get along so well. "The fact that they actually like each other is even better because if they did not, that could be a bit tumultuous."

The Emmy-winning actor continued, "Susan Kelechi Watson is incredibly talented, a warm and loving human being and Ryan Michelle Bathe is my best friend. I mean, that is my homie, we go way back. We have two beautiful kids together. I am having a good time with everybody."

MORE: 'This Is Us' Stars Break Down 'Special' Jack-Rebecca Flashback Episode: It Was a 'Magic Moment'

Justin Hartley, who plays Brown's adopted brother, confessed that their TV bromance is even stronger on set. "For a show that makes everyone cry, we are laughing 90 percent of the time, at ourselves, at each other," he said. "It is a great camaraderie on set. We take care of each other but we definitely laugh a lot as well."

Hartley, who is getting married this spring to 35-year-old actress Chrishell Stause, joked that he is disappointed that Brown has not bestowed any wedding advice onto him.

"You'd think that he would give me just a little bit though, you know what I mean? Hey bro, a little bit of advice?" Hartley said with a laugh. "He's busy. He's shooting something or he's, like, winning an award or something. He's busy."

Moore added, "We just enjoy each other's company. I'm happy to be at events like this where we can all be together. We're all here to celebrate the good news together."

The good news she's referring to is the fact that This Is Us has been renewed for not one, but two more seasons at NBC. "I can't really digest that or wrap my head around it right now," the 32-year-old singer-turned-actress divulged. "I think we all -- we just keep giving each other eyeballs, like, 'What?! What is happening?!'"

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

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