Robert Redford ensured his safety during a love scene with Barbra Streisand in their 1973 film “The Way We Were” by wearing two athletic supporters, according to a new book by Robert Hofler titled “The Way They Were: How Epic Battles and Bruised Egos Brought a Classic Hollywood Love Story to the Screen”.

The book details the challenges that the cast and crew faced during the film’s production, from on-set tensions to countless delays and rewrites.

Hofler explains that Redford, a happily married family man with four children, was reluctant to work with Streisand and chose to double up on the jock straps “to protect himself in more ways than one,” while Streisand “chose to don a bikini.”

Reps for Redford, 86, and Streisand, 80, have not commented on the claims made in the book.

Assistant director Michael Britton said that “it was a pretty G-rated scene,” and that producer Ray Stark cautioned that he did not want “a heavily shadowed n/de scene.”

The film was going to be rated PG, and a “f—” was deleted from the script to avoid “a dreaded R rating.”

The intimate scene was supposed to be a simple one to film on a closed set.

However, Britton said, “there were a lot of takes.” At one point, Redford looked at director Sydney Pollack, implying he had enough.

Redford would later joke to a Newsweek reporter that the only thing he wore on set for the scene was “Aramis,” the Estée Lauder fragrance for men.

Redford, who was playing a “Ken doll,” was allegedly wary of Streisand from the start.

The actor told Pollack he did not believe Streisand was “a serious actress” because she “had never been tested.”

The book claimed that Streisand was “infatuated” and “mesmerized” with her co-star.

“Barbra Streisand was a star who reportedly had affairs with many of her leading men,” said an unnamed member from the film set.

During their second love scene, Redford allegedly refused to say the line, “It will be better this time,” because he felt people would assume he was not a good lover.

Redford and Streisand could not be more different on set.

“Barbra wanted precision; Redford, spontaneity,” said Pollack.

“Barbra likes lengthy rehearsals and multiple takes.

“Redford is better in his early takes.

“Streisand, a leading man who happily ditched premieres on both coasts and mixed critical reviews.”

The book also revealed that it took eight months of “incessant wooing” from Pollack for Redford to finally sign on.

Ryan O’Neal was at one point another name being considered for the film.

Eventually, the stars settled into their roles, and for their first reading, it was like a “lightning bolt” went off in the room.

Editor John Burnett was said to be “amazed at how much footage he had to work with to put together the simple lovemaking scene.”

However, there may have been another reason why Redford was wary about the love scene.

Hofler claimed that Redford was reluctant to work alongside the “Funny Girl” star, and when it was time to get in bed with Streisand, the Hollywood heartthrob did not take any chances.