Rachel McAdams on Bringing Her Son to Set of Her First Movie Since Becoming a Mom (Exclusive)

Rachel McAdams is opening up about her new experience as a working mom.

Rachel McAdams is opening up about her new experience as a working mom.

ET's Kevin Frazier spoke to the 41-year-old actress about her new film, Eurovision Song Contest: The Story of Fire Saga, which she stars in opposite Will Ferrell. Ferrell and McAdams play Icelandic singers in the comedy, who are given a chance to represent their country at the Eurovision Song Contest.

McAdams talked to ET about shooting the film in Iceland and Scotland, and about actually getting to bring her young son along. The movie marks the first film she's done since giving birth to her son in 2018, whom she shares with her boyfriend, screenwriter Jamie Linden.

"Yeah, I got a lot of time off beforehand so I was pretty ready to go back by the time I did," she tells ET. "He was almost two ... but I mean, being able to take him to Iceland, he'll never remember any of it but I feel like somehow that might stick to his soul and his personality a little bit, so it was great to get to travel. And you know, we've been sort of cuddled up for so long together that it was wonderful to go out into the world and get to work at the same time. I felt really lucky to be able to do that."

McAdams said she and her family are now currently making the best of their time together during the coronavirus pandemic.

"Yeah, I mean, it's a lot of quality time but ... it's something that you'll never get to do quite like this again," she shares. "It's such extraordinary circumstances and, you know, we're just making the best of it and I was reading something about that in The New York Times, like, don't worry about your kids because he was just starting to really talk and open up and socialize. Don't worry, you know, the time they're getting and they're learning other skills that will benefit them just as much as socializing so just you know, relax, it'll be OK."

Meanwhile, McAdams also talked about having a lot of fun filming with 52-year-old Ferrell.

"Yeah, he's the loveliest mad man ever," she jokes. "I mean, I'm just such an admirer of his and always have been and I just think he's the funniest man on the planet and then, you know, he's so warm and lovely as well. We just really had a great time. Sometimes movies that look fun aren't actually fun, behind the scenes."

The feeling is definitely mutual. Ferrell told ET his co-star was "exceptional."

"You know, we had never really worked together other than we were in Wedding Crashers together but we never worked on the same day and she's just as nice and as good as anyone I’ve ever worked with and just kind of had to be thrown into, you know, from day one between rehearsals and music and dance rehearsal and all this stuff," he notes of McAdams. "She was just kind of thrown into the fire and she's just, she's exceptional. She's great with the comedy beats. She also gives such heart to the movie."

ET also talked to Pierce Brosnan, who has a role in the film but doesn't get to sing. The 67-year-old actor hilariously said he tried to convince the crew to let him sing by showing off his accomplishments in 2018's Mamma Mia! Here We Go Again.

"I must say, I did bring in my platinum album, my gold album and said, 'Look, I got this from Mamma Mia, why don't I have a song here, guys?'" he cracks. "I think Will got a little bit ... I think he just got a little bit sensitive about that, and you know, ego."

"In many respects I'm glad they didn’t ask me to sing," he continues. "You know, this is a fabulous film. I'm very proud to be a part of it. I’m a huge fan of Will Ferrell's work, Rachel McAdams, and we've worked together before and she's just the dynamite actress -- incredible -- and, you know, the film's got heart. Some people don't know about the Eurovision Song Contest. It's been going for 57 years in Europe. It's like America's Got Talent or The Voice and all the countries come together and they put their best performers, acts, up on the stage and they battle it out and it's the birthplace of ABBA."

Eurovision Song Contest: The Story of Fire Saga streams on Netflix June 26.