Even Kate Upton can be uncomfortable in a bathing suit. Specifically, while running on a beach in a skimpy white bikini for her first feature film role in "The Other Woman."
"It was funny because when we were filming that scene, you know, whenever you go to a beach, everyone's wearing bikinis, so it's just pretty normal. It's just part of life," said the 21-year-old, who was joined by costars Cameron Diaz and Lesilie Mann on "Good Morning America" on Wednesday.
- Kate Upton: Cover girl to glamour girl
- Kate Upton, Cameron Diaz, Leslie Mann scheme in 'Other Woman' trailer
- Mann goes for Diaz's bum, not Upton's, at 'Other Woman' premiere
- 50 most beautiful female celebrities
- Our favorite funny women and why we love 'em
- The Other Woman (movie)
- Cameron Diaz
- Leslie Mann
"But when you're filming a bikini scene, nobody's wearing a bikini. It's only you and 60 crew members," she added.
The difference between a movie set and a swimsuit shoot, Upton said, is that the latter includes only about "five people" with whom she already has a history. Turns out, the Bobbi Brown spokeswoman had an additional mini-crew of her own thanks to her costars, who decided to jump in to make her feel less jittery about the likely-to-be iconic running scene.
"These two saw that I was feeling a little uncomfortable -- because anyone's uncomfortable when that many people are staring at you -- but these two came and ran beside me offscreen," she said. "I've never had support like that before and it was just so amazing that I got that on my first film experience."
That's a sentiment the voluptuous model brought up at the film's London premiere in early April, saying she considers her costars "very close friends" who have been supporting her formative film years in a way she didn't get during her early years in the modeling industry.
"The Body Book" author Diaz, who's starred in many a chick flick, said her rookie costar was "fearless" and "really went for it" in the film.
The support factor was something that plays both offscreen and onscreen in the comedy, which is about three women's unlikely bond when they're brought together by a man they're all involved with, played by "Game of Thrones" star Nikolaj Coster-Waldau. Diaz plays his mistress, Mann plays his wife and Upton plays his latest plaything.
"Charlie's Angels" alum Diaz chimed in about the film's meaning against the backdrop of the female gender in an industry "inundated with these ideas that women hate one another and that they're competitive."
"We have so many examples of that on television where there's just women constantly stabbing one another in the back even when they're supposed to be friends," the 41-year-old said.
"This [film] is about three women who are brought together by this weird circumstance of all being involved with the same man," Diaz explained. "Instead of hating one another and stabbing one another in the back, they put the onus on the man because he was the liar and the cheater and they join forces basically. They do what women do, which is take care of each other and help each other through a hard time."
And that's something Upton said Diaz and Mann did for her repeatedly on set.
"This is my first movie role, and these two supported me every step of the way," Upton said. "They made me feel so safe from Day 1. They encouraged me to mess up and try new things and they were just amazing examples."
"The Other Woman" inundates theaters on Friday.
Follow Ministry of Gossip @LATcelebs.