Loretta Young wasn't married to Clark Gable. They had an affair, Loretta became pregnant out of wedlock and secretly gave birth to daughter Judy. Here's the skinny from Wikipedia:
Affair with Clark Gable
In 1935, Young had an affair with Clark Gable, who was married at the time, while on location for The Call of the Wild. During their relationship, Young became pregnant. Due to the moral codes placed on the film industry Young covered up her pregnancy in order to avoid damaging her career (as well as Gable's). Returning from a long "vacation" (during which she secretly gave birth to her daughter), Young announced that she had adopted the infant girl. The child was raised as "Judy Lewis" after taking the name of Young's second husband, producer Tom Lewis.
According to Lewis's autobiography Uncommon Knowledge, Lewis was made fun of because of the ears that she received from her father, Clark Gable. In the documentary Girl 27, she states that, at 7, she had an operation to "pin back" her large ears and that her mother always had her wearing bonnets as a child. Over the years she had heard rumors and secretly knew that Clark Gable was her biological father, but it was not until 1958 when Judy's future husband Joseph Tinney told her that "everybody" knew the rumors that she really began to suspect.
Several years later, after becoming a mother herself, she finally confronted her mother, who, after promptly vomiting, admitted to her true parentage, stating that she (Judy) was a "just a walking mortal sin."
