"It was funny because when we were filming that scene, whenever you go to a beach, everyone's wearing bikinis, so it's just pretty normal. It's part of life," the Sports Illustrated model said. "But when you're filming a bikini scene, nobody's wearing a bikini, it's only you and 60 crewmembers. And these two saw that I was feeling a little uncomfortable, because anyone's uncomfortable when that many people are staring at you."
"This was my first movie role and these two supported me every step of the way," Upton said. "They made me feel so safe from day one. They encouraged me to mess up and try new things and they were amazing examples."
Upton said she didn't feel she was in the best shape for the sexy scene.
"Of course, I always try to live a healthy lifestyle, but that was my birthday week," she said. "So that was the least healthy I've ever been. I just turned 21...Cameron, Leslie and I were just living it up that week."