Hot Frosty's Lacey Chabert Struggled to Keep a Straight Face While Filming: 'I'm the Worst at Not Laughing' (Exclusive)

Lacey Chabert had a tough time keeping her composure while filming her latest holiday movie.

The actress, 42, stars in the new Netflix rom-com Hot Frosty — which features a hunky snowman brought to life — and tells PEOPLE there were "so many takes that turned into outtakes" because she "couldn't stop laughing."

"Craig Robinson, Joe Lo Truglio, Lauren Holly, Katy Mixon — everybody's just so, so funny, and we had such a blast on set," Chabert raves of her costars. "It was just a really joyful environment."

Faced with the comedic performances of the cast, Chabert says she couldn't keep a straight face during some scenes. "I'm the worst at not laughing when you're not supposed to," she admits. "So there were many a take that I accidentally ruined because I broke and laughed."

But she says all the laughter on set not only made for a fun and memorable filming experience, but ultimately elevated the movie, which premiered on Nov. 13. "You know what? That joy that's created on set when you're entertaining each other, I really think that is infectious and comes through the screen," she explains.

"I think the whole movie has a really fun undertone to it. These characters are in on the joke in a way themselves, and they're not taking it too seriously," Chabert adds.

Chabert was not alone in getting the giggles. Leading man Dustin Milligan, who plays the chiseled snowman incarnated by a magic scarf belonging to Chabert's character, widow Kathy Barrett — also "broke" character while shooting some of the funnier scenes.

"Our director, Jerry Ciccoritti, encouraged all of us to improvise throughout filming, and even though so much of it never made the final cut, making each other laugh was basically the goal of every day," Milligan, 39, tells PEOPLE. "Everyone broke at one point or another, and it was a privilege to do so in such good company!"

Chabert praised Milligan for being "brave" and really digging into his role as Jack Snowman. "He has an incredible gift for physical comedy, and he's also just really brave. He's a wonderful actor, and he was willing to totally commit and go for it, and that's what this character needed," she says.

"He's just so free. He was willing to try anything, I feel like, in the takes and in his performance, and that's kind of a vulnerable thing to do, and he was just wonderful," Chabert continues.

While Milligan embraced the physical comedy of the role, he says his shirtless scenes brought up some "insecurities" about his body. But he pushed himself to just "let go" and stay in the moment.

"Exposing my body on camera brings up a lot of insecurities and body-image issues I have. So in order to do a character like Jack justice, I had to let go in a way I've never done before and just be fully physically liberated in every single scene, which simultaneously challenged the discomfort that being so exposed brought and allowed the pure joy I was feeling shine through," the Schitt's Creek star explains.

Chabert previously spoke to PEOPLE about Hot Frosty's improbable love story, which finds Kathy trying to help Jack navigate the real world while he encourages her to rediscover romance and laughter — before he melts away.

"This romance definitely has some challenges that they'll both have to overcome," Chabert told PEOPLE.

"[But] Jack's childlike, playful quality and excitement of being alive really brings out Kathy's playfulness and really reminds her about what she loves about the holidays," she added. "It reminds her of what it is to just connect with someone and reminds her that she needs to put herself back on the list of things that are priorities."

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Hot Frosty is available to stream on Netflix.