The Surprising Way Brie Larson Scored The Part Of Amy Schumer's Sister In 'Trainwreck'

Emily Tess Katz

Note to actors: When Judd Apatow calls you out of the blue to go to lunch, (obviously) say yes.

Just ask "Room" actress Brie Larson, whose audition process for "Trainwreck" consisted of lunching with Apatow alongside the film's writer and star, Amy Schumer.

"I didn't really understand what was going on," she told host HuffPost Live on Wednesday. "Judd had called me on my cell phone -- which I still don't know how he had my number -- but he called me and said he was working on a movie with Amy and asked if I wanted to come have lunch with him. I didn't really know what it meant."

After opening up to Apatow and Schumer about her life and her relationship with her own sister, the two extended an invitation for lunch the following day.

"I was like, 'OK, great!'" the "Room" actress recounted. "I got in my car and called my agent and manager and they're like, 'So, why were you there?' I said, 'I don't know. They want me to come back for lunch tomorrow!' And they were like, 'Why?' I was like, 'I don't know -- maybe they're bored and want some entertainment!"

"It took about a week before I slowly started thinking, 'Oh, am I going to be in this movie?'" she added, a bonus given that she was excited to just be in their company.

"I was getting free lunch with the two of them. What could be better than that?" she laughed. "I was perfectly fine with that. [Judd]'s office isn't that far from my house, I got a free salad out of it. Like, whatever!"

The casualness of her audition process is indicative of Schumer's laid-back style, says Larson.

"There was no formal thing [because] there's no airs," she said. "[Amy's] in her daily life [in a] T-shirt, no makeup, hair in a ponytail, but will make you pee your pants with laughter."

Watch more from Brie Larson's conversation with HuffPost Live here.

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