Mandy Moore Reveals Surprising Facts About Her 'This Is Us' Costars: 'We're One Big Goofy Family'

Though she makes viewers weep on screen, it’s anything but tears off-screen for Mandy Moore and her costars.

“I love everybody. We’re one big, goofy family,” Moore, 35, tells PEOPLE of the cast and crew behind NBC’s era-jumping family hit This Is Us.

The actress, who received her first-ever Emmy Award nomination this year, revealed surprising behind-the-scenes facts about Milo Ventimiglia, Sterling K. Brown, Susan Kelechi Watson, Justin Hartley and Chrissy Metz after a photoshoot for PEOPLE’s 2019 Emmy portfolio, “The Greatest Stars on Earth.” (To see the entire portfolio, pick up the new issue of PEOPLE.)

“Milo is an incredible snacker,” Moore, who plays matriarch Rebecca Pearson, says of her TV husband. “Often at work, he’ll look at me and he’ll be like, ‘Snack attack?’ And I’ll be like, ‘Snack attack,’ and we’ll go to craft service. He has a different palate than I do. I think we both encourage each other when the time is right to sort of up the sugar ante and we’ll do like Nerds and Sweet Tarts, which is definitely not like my go-to, but for some reason, Milo brings that out at me.”

Both Ventimiglia, 42, and Brown, 43, consecutively earned lead actor nominations for their roles as Jack and Randall Pearson, respectively.

“Is there nothing that Sterling can’t do? He’s larger than life in every way and in the best way. I’m often surprised at his sensitivity,” Moore says of her on-screen son Brown, who has a “very tender soft side where he’s vulnerable and wants to talk about real-life stuff.”

“He’s someone that I know I can go to and have a conversation about the real in life. And he’s always down to lend an ear. He gives great advice. I mean, I’m sure people aren’t surprised by that. … He’s the ultimate entertainer,” she says, adding, “If he ran for president, I would vote for him without even thinking about it.”

As for the class clown of This Is Us?

“Justin is the most low key, unexpectedly funny person, he cracks me up,” she says. “I was working with him, John Huertas and Chris Sullivan. It’s a problem working with Justin and those two because I know I’m just going to be laughing too much, and the makeup team is always pretty upset with me.”

Moore adds, “I know that when I’m in my prosthetics, it’s going to be a problem because the more you talk, move your mouth, laugh, chew and all of that, it sort of breaks them down.”

And the ladies on set are some of Moore’s closest confidantes.

“Susan is sort of the heartbeat of our family, which wouldn’t be surprising considering the character that she plays. She is the person that I feel soulfully connected to,” she says of Watson, who portrays daughter-in-law Beth Pearson.

“I don’t get to work with her as much as I would like. I’m always excited when present-day Rebecca has scenes at Randall’s house because it means that most likely I’m going to get to hang with Susan and the girls. She’s someone I also feel like I could go to and talk about real-life stuff with,” Moore says. “She and Sterling, I think people know this too, are incredible dancers, her especially. She’s remarkable, she’s the coolest. She’s so quiet and like feline-like. I love Susan so much.”

Last but not least: Metz has her on-screen mom Moore in stitches on set.

“She’s an incredible singer. She’s also hilarious. Like she’s really good at doing voices and characters. She’ll bust into some sort of funny voice or something unexpectedly. And she always has me giggling,” Moore says.

“Maybe it’s the nature of the show and the material, but we all can really like dig into stuff with each other and talk about the real stuff that’s happening in our lives. And she’s probably the person that I do it with the most, just because I spend the most amount of time with her. We’re both Florida girls, so we have that sort of connection between us,” she adds.

Season 4 of This Is Us premieres Sept. 24 on NBC.