Interesting Information on the film found on the TCM website

Forever, Darling (1956)

The phenomenal success of the television series I Love Lucy had convinced MGM to star Lucille Ball and Desi Arnaz in a feature film, The Long, Long Trailer (1954). It was also a hit, one of the biggest of the year. Studio head Dore Schary then offered the couple a two-picture deal, with terms highly favorable to Arnaz and Ball. The first film would be shot at the Motion Picture Center, Desilu's studios, which would increase their profit participation, and establish the company as a feature film producer. In addition, Arnaz would produce the film, which would be a joint production of MGM, Desilu, and the Ball-Arnaz company, Zanra. In exchange, MGM would receive big plugs in the forthcoming I Love Lucy episodes in which the Ricardos go to Hollywood. In the show, "Ricky Ricardo" would be signed to star in an MGM film.

For the first film in the deal, Schary suggested a property the studio had bought in the 1940's as a vehicle for Spencer Tracy and Katharine Hepburn -- about as far from Lucy and Ricky's personas as MGM was from TV sitcom. Extensive revisions would be necessary. In Forever, Darling (1955), Arnaz plays a research scientist so involved in his work that he neglects his wife, Ball. Her guardian angel, who happens to look like her favorite movie star, intervenes to save the marriage. The couple wanted Cary Grant to play the angel, but he was too expensive. The suave James Mason got the role, and played it elegantly. Two decades later, Mason would play a similar celestial creature in Warren Beatty's Heaven Can Wait (1978).

Lucille Ball was well known for her loyalty to old friends and colleagues, and she hired one of them to direct Forever, Darling. Alexander Hall was an old boyfriend and mentor of Lucy's from her starlet days in the 1930's. In fact, she'd dumped Hall when she met Arnaz, but they'd remained friends. Hall had not worked much recently, and was happy to get the job. But one Desilu executive recalled that "they hired Al Hall, but wouldn't let him direct." As they were used to doing, Ball and Arnaz ran the show, and brought in I Love Lucy writers Madelyn Pugh and Bob Carroll for some uncredited script doctoring. All their efforts, however, didn't help the film. Officials at Radio City Music Hall called Forever, Darling "substandard," and refused to premiere the film there. Instead, it opened at Loew's State, where the newlywed couple had performed their first vaudeville act in 1941.

Reviews were not good, and Forever, Darling was a disappointment at the box office, barely returning its production cost of $1.4 million. By mutual agreement, Ball, Arnaz and MGM cancelled the second picture in their deal. Plans for Desilu to move into feature film production were dropped as well, and the couple went back to doing what they did best, I Love Lucy.

In spite of Forever, Darling's failure, it left a lasting legacy to the Arnaz family - the tender title song, with music by Bronislau Kaper and lyrics by Sammy Cahn. It became a family tradition, sung by Desi at anniversaries and other events, a tradition that endured long after the marriage ended. When he sang it at daughter Lucie's wedding to actor Laurence Luckinbill, his ex-wife wept, and they hugged and kissed after the song.

This was written by Margarita Landazuri and posted on the TCM website.