Gone With The Wind - Part Three

During the 1930's, there was a very stringent morality code in Hollywood.

Per Wikipedia:

The Motion Picture Production Code was the set of industry censorship guidelines which governed the production of the vast majority of United States motion pictures released by major studios from 1930 to 1968. It was originally popularly known as the Hays Code, after its creator, Will H. Hays

The Motion Pictures Producers and Distributors Association (MPPDA), which later became the Motion Picture Association of America (MPAA), adopted the code in 1930, began effectively enforcing it in 1934, and abandoned it in 1968 in favor of the subsequent MPAA film rating system. The Production Code spelled out what was acceptable and what was unacceptable content for motion pictures produced for a public audience in the United States.
The office enforcing it was originally popularly called the Breen Office, named after its first administrator, Joseph I. Breen.

One famous instance in GWTW, was the last line delivered by Rhett Butler: "Frankly my dear, I don't give a damn" (by the way, it was Selznick who added the word "Frankly"). The association tried valiantly to have the word "damn" removed. Selznick insisted on keeping it in.

Again, per Wikipedia:

Prior to the film's release, censors objected to the use of the word "damn" in the film, a word that had been prohibited by the 1930 Motion Picture Association's Production Code that began to be enforced in July 1934. However, before 1930 the word "damn" had been relatively common in films.[2] Although legend persists that the Hays Office fined producer David O. Selznick $5,000 for using the word "damn," in fact the MPA board passed an amendment to the Production Code on November 1, 1939, a month and a half before the film's release, that forbade use of the words "hell" or "damn" except when their use "shall be essential and required for portrayal, in proper historical context, of any scene or dialogue based upon historical fact or folklore … or a quotation from a literary work, provided that no such use shall be permitted which is intrinsically objectionable or offends good taste." With that amendment, the Production Code Administration had no further objection to Rhett's closing line.[3][4] It is actually the second use of "damn" in the film. The term "damn Yankees" is heard in the parlor scene at Twelve Oaks.

There were other, behind the scenes occurances of "Deceny" code being enforced.

At the beginning of the filming of GWTW, Clark Gable, who was still legally married to his 2nd wife, was being seen in public and private with actress Carole Lombard. Gable's wife, Ria Langham, refused to give The King (as he was referred by) a divorce. In order to get her to change her mind, Louis B. Mayer, offered Ria a substantial settlement to divorce Gable. She then willingly agreed. Clark Gable was then free to marry Carole Lombard, which he did in early 1939.

Another situation, was Paulette Goddard's marriage to Charlie Chaplin. She was asked to produce a marriage certificate, which either she never had in the first place or just refused to produce, period.

There was a bit of a double standard though. At the time of the filming, Vivien Leigh, who was legally married to another man, was having an affair with Laurence Olivier.