EXCLUSIVE: Hollywood's Biggest Stars Reveal Their Secret Friendships

These dynamic duos prove that a little teamwork goes a long way.

See as RadarOnline.com ​​reveals who they are.

'Butch Cassidy and the Sundance Kid'

"It turned into a longtime friendship," said Robert Redford of Paul Newman, who fought for him to play his bank robber buddy in 1969. "Nothing has sustained like our connection. It went [from] movie friendship into personal friendship. It cut very deep. He changed my life."

'Some Like It Hot'

Tony Curtis once said that if it weren't for costar Jack Lemmon, making this 1959 classic about musicians who go on the lam as women would have been a real drag. "Neither Jack nor I liked sitting in a makeup chair too long. So we'd lie back in those chairs and reach across and hold each other's hand. We'd just hang on to each other."

'Midnight Run'

They made jumping bail fun in this 1988 comedy, but the bond between Robert De Niro and Charles Grodin was serious. "Once he knew kind of where I was coming from, he started to open up," said Grodin. "And we really developed a nice friendship."

'Dumb and Dumber'

For Jim Carrey, you didn't need to be a genius to know Jeff Daniels was perfect to play doofus Harry to his dope Lloyd in this 1994 flick. "As soon as we started reading together," Carrey said, "it was a real relationship."

'Outrageous Fortune'

"It was rough. It was pretty rough," admitted Bette Midler, who butted heads with costar Shelley Long during the filming of this 1987 farce about two women out to track down the same man. But in the end, "she did a good job, as it turned out, [and] it was very successful for both of us."

'Grumpy Old Men'

"One thing is a constant. Whenever I was with Walter, whether it was in a film or personally, it was always a magic time," shared Jack Lemmon of pal Walter Matthau. And no better proof was their turn as constantly feuding codgers in this 1993 pic, one of the best of their eight comedies together.

'Lethal Weapon'

They played mismatched cops in this 1987 hit and its three sequels, but Mel Gibson and Danny Glover insist they make a perfect pair. "Our advantage is that we really do enjoy each other's company," Gibson said. "I get him, and he gets me."

'Thelma & Louise'

Much like the on-the-run duo of this 1991 pic, Geena Davis and Susan Sarandon "keep going" with the friendship they developed on set. Said Davis: "[My character, Thelma] counts on Louise to help her and look out for her. That was definitely how we were in real life, too... And still are."

'48 Hrs.'

Their cop and convict may have come to blows in this 1982 flick, but director Walter Hill recalled that Nick Nolte and Eddie Murphy "got along great. They loved each other. In fact, they would attack me on set every day complaining about the script."