While real-life outlaws Butch Cassidy and the Sundance Kid were closely bonded, actor Paul Newman revealed that at the time filming, he had some resentments over the young Robert Redford.

A real testament to their acting skills, Newman, playing Robert LeRoy Parker or “Butch Cassidy,” and Redford as Harry Longabaugh “Sundance Kid,” were persuasive in their portrayals of the Wild West buddies, notorious criminals who were on the run from the law after a string of bank and train robberies.

The 1969 movie about the real-life outlaws won four Oscars and holds up as one of the greatest Westerns ever made. Four years later, the stars–both handsome heartthrobs–partnered up again for another caper film, The Sting (1973).

Newman and Redford are both legends and together, they made magic happen. But have you ever wondered how the Hollywood stars got along off the set?

Newman, who played Butch when he was 44, confessed that he wanted the role that was played by the younger Redford, who at the time was 33.

In an interview with BBC’s Talking Pictures, Newman said, “We have a lot of fun together, we bounce off each other real well.” He continued, “I would have preferred to have played Sundance. I feel a little more comfortable with that cooled-out kind of quality. I suppose it’s the easier part!”

Redford was a rising star, whose performance alongside Natalie Wood in the 1965 film Inside Daisy Clover, earned him a Golden Globe for New Star of the Year.

Newman had already reached superstar status after appearances in films like Cat on a Hot Tin Roof with Elizabeth Taylor (1958) and Cool Hand Luke (1967).

It was after Steve McQueen turned down a part in Butch Cassidy and the Sundance Kid–he later turned down Dirty Harry (1971), The French Connection (1971) and One Flew Over the Cuckoo’s Nest (1975)–when Redford was cast, playing next to Newman, who was collecting awards in both acting and directing.

The BBC reports that according to Newman’s biography, “The Extraordinary Life of an Ordinary Man: A Memoir,” the two stars weren’t really friends at the time.

Newman said, “You can’t depend on Redford. You’re never sure he’s going to be there. That’s simply discourteous.”

Newman’s youngest daughter, Claire Newman Soderlund–whom he fathered with his second wife Joanne Woodward–said she believes that their tensions were a result of contrasting approaches to work.

She said, “My father was very much a stickler for timeliness and Bob, that was never really his strength. It was hard work for dad. He worked very hard at it because he wanted to be good and he wanted to be successful and Bob was more of a free spirit.”

When Newman died of lung cancer in 2008, Redford, now 86, spoke with ABC News and said, “It was just that connection of playing those characters and the fun of it that really began the relationship,” he said, reflecting on Butch Cassidy and the Sundance Kid. “And then once the film started, once we went forward, we then discovered other similarities that just multiplied over time, a common ground that we both had between us, interests and so forth, and differences.”

After playing the iconic outlaws and then cons in The Sting, Newman and Redford explored opportunities to work together on a third film, but it never came to fruition.

It almost happened in A Walk in the Woods, the 2015 film adaptation of Bill Bryson’s 1998 book of the same name. Another buddy movie, the story follows two out-of-shape older men and their goal of hiking the rugged Appalachian Trail.

Redford, who starred and produced the film, selected this script in 2005, with his real-life buddy Newman in mind.

Speaking with Yahoo in 2015, Redford said, “It started with Paul, because Paul and I had been looking for a third film to do together. A lot of time had gone by, and I just couldn’t find it. When I read this book… I thought of Paul right away.”

Redford, 79 at the time of the interview said he sent the book to Newman, who wasn’t confident he could meet the physical demands of the role, which was later given to Nick Nolte.

The connection between Newman and Redford, both highly acclaimed actors, grew considerably since they first filmed Butch Cassidy and the Sundance Kid.

Becoming like brothers, the actors lived in Connecticut, only one mile apart from each other and their families are also close.

Speaking after his buddy died, Redford said, “We both got to know each other’s flaws pretty well. Of course, I outweighed him on that front. But knowing each other’s flaws, we just played them to the hilt and we’d try to trick each other. We’d try to surprise each other, and it was so damn much fun that it became like–it became like a scenario unto itself.”

He added, “Paul really likes to have fun and he loves to laugh and he really especially loves to laugh at his own jokes, and some of them are just really awful. So the fact that he enjoyed them so much, you forget about the joke and you’d start to laugh with him because you’re so caught up in his enjoyment of them.”

Paul Newman and Robert Redford had so much chemistry playing the timeless duo! Tell us what you think about their on-screen relationship and their real-life buddy love!