But before celebrities make their way on to the red carpet at the Metropolitan Museum of Art in New York City Monday night, Olivia Munn is giving ET an exclusive sneak peek at what it's like to get ready for fashion's biggest night.
The 37-year-old actress invited only ET to hang out with her during her glam session at the Carlyle Hotel. The theme of this year's soiréeis "Heavenly Bodies: Fashion and the Catholic Imagination," exploring the relationship between fashion and masterworks of religious art, and we think it's safe to say Munn's interpretation is on point.
The brunette beauty chose a daring, sleeveless chainmail dress, custom-made by H&M, that drapes on the body like liquid. The golden chainmail was cut long and lean, with a plunging neckline and open sides, held together by links of golden rings."
"[It was] love at first sight," Munn, who is styling the piece with gold Christian Louboutin pumps and a stunning headdress created by Michael Schmidt, explained. "We do have this built-in corset, because we wanted to have this feeling of armor and have everything pulled in together."
Before she slipped into the dress, Munn told us that she had been pregaming the ball by indulging in some of her favorite sweet and salty treats, like French fries and cookies. "It is something that gives me a lot of stress," she confessed. "I see people working out nonstop on Instagram, talking about their cleanses, all for the Met Ball and I've had French fries the last two nights."
"Every time people talk about how good they are, I want to be bad," she joked.
As Munn continued to get ready, ET grilled her on behind-the-scenes Met Gala secrets, along with her favorite memories from attending the star-studded fashion party over the years.
"The real kind of freakout happens when you're on the red carpet and you're looking around," she shared. "My first time I went there ... you're looking around and there's the most famous people all around you, and I literally felt like I won a radio contest. I'm just standing there. It's very overwhelming at first when you see it, but it was very cool."
"Honestly, the bathroom at the Met is really interesting because you go in there and there's, like, everyone," she continued. "It can bring up some high school anxiety, where you're like the new girl and you're like, 'Ugh.' But you learn to blend in and just watch."
Munn added that she'll also never forget her second-ever Met Gala, when she walked the red carpet right before George Clooney and his wife, Amal, who is co-chairing this year's event with Rihanna, Donatella Versace and Anna Wintour.
"At first people were screaming, 'Olivia, Olivia! Over here, over here!' And then, within seconds, somebody goes, 'You -- move!' and I was like, 'But you were just saying nice things to me.'"
"I look over my shoulder and it's Amal and George, and I thought it was the funniest [thing]," she continued. "I was like, 'This is literally the highlight of my night.'"
ET also caught up with Munn on the red carpet, where she couldn't help herself from gushing over how her entire look came together.
"Honestly, it's been such an amazing day today, and it's been a long day, but it's exciting to see it all pulled together and that everything has worked out," she said. "This look is head-to-toe chain metal. So, it's very heavy and we were inspired by the crusades. I love this dress."
As we patiently wait to see what the other A-listers will be wearing, watch the video below to hear why Beyonce won't be present at this year's gala.