'Small-town boy': Nova Scotia's James Tupper gets big role on 'Big Little Lies'

James Tupper, left, and Anne Heche arrive at the Los Angeles premiere of "Big Little Lies" at the TCL Chinese Theatre on Tuesday, Feb. 7, 2017. (Photo by Jordan Strauss/Invision/AP)

TORONTO -- Nova Scotia native James Tupper says being among the group of A-list stars on HBO's hit "Big Little Lies" is the best thing that's happened to his career.

And he credits a fellow Canadian -- Quebec's Jean-Marc Vallee, who directs the show -- with giving him the opportunity.

Tupper plays the easygoing ex-husband to Reese Witherspoon's acerbic character in the darkly comedic murder mystery, which creator-writer David E. Kelley based on Liane Moriarty's bestselling novel.

Other cast members on the limited series include Nicole Kidman, Shailene Woodley, Laura Dern, Zoe Kravitz, Alexander Skarsgard and Adam Scott.

"I'll always be a small-town boy from Dartmouth, Nova Scotia," Tupper says from Los Angeles, noting his East Coast family is practically speechless over his success on the show.

"My aunts can't even speak to me -- I call them ... 'Hello? Jimmy, I can't believe it. I can't believe it.'

"But just to be in that group of names is obviously the best thing that's happened to my entire career. When you get up to that level, I call it the NBA level, like the top level -- everybody is very, very good at their job and very open about working with people. They want the thing to work and they're supportive and give it every reason to succeed."

The former star of "Men in Trees," "Revenge" and "Aftermath" says Vallee was his advocate from the beginning when he auditioned for the role of Nathan on "Big Little Lies," which follows the complicated lives of three mothers after a murder in the seaside town of Monterey, Calif.

"Jean-Marc is one of the most open and giving human beings and I feel like when I went in and auditioned for this, he was one of the really big reasons I got it," says Tupper, "because people in Hollywood tend to want to cast a big star or a big name and he was just like, 'No, you're perfect for this and this is exactly right for you and I want you to do it."'

Vallee's other directing credits include "Dallas Buyers Club," for which he got an editing Oscar nomination, and "Wild," which earned Witherspoon and Dern Oscar nominations.

"I'll tell you frankly, and I'm not exaggerating: he's one of the humblest, kindest, most intelligent people I have ever met," Tupper says of Vallee.

"One day this guy was there ... walking around set and I'm like, 'Hi, what's your name? ... What do you do on the film crew again?'

"And he's like, 'I met Jean-Marc at a dinner party about a week ago and I mentioned to him that I really want to become a director and he said, "Come on set and tail me for the week.""'

Tupper says Witherspoon slyly established the bitter chemistry between their characters, who share custody of their children -- before the cameras even started rolling.

"She was like, 'Hi, James,' she was very pejorative, a bit caustic," he says with a laugh.

"So we would get into the scenes and we'd do them and at the very end she opened up to me in this lovely way, because she's such a sweet and earnest and open person, and we ended up now having a friendship.

"But the whole time we were doing it I wasn't quite sure. I was like, 'Uh, hi, Reese."'

The show is making headlines for its realistic portrayal of domestic violence, based on a storyline involving the characters played by Kidman and Skarsgard.

"You get a chance to delve into the psychology and that's one of the things I'm probably proudest of," says Tupper.

"If you get to participate with a group of artists and make something that's really truthful, that's about the highest you can go, in my opinion. They don't skim the surface.... It's really gnarly."

The seventh and final instalment of "Big Little Lies" airs Sunday on HBO Canada and Tupper -- who would only reveal that he and Kravitz sing in the episode -- will be watching.

"It's the only time I've had a viewing party," he says. "Every Sunday a bunch of my friends come over and we order pizza and watch it."