Was Nancy having an affair with her boss? (spoiler alert)
Are we to assume that Nancy was, contrary to her protestations, having an affair with her boss? The Robert Mitchum character thought she was, and of course he turns out to be right about her. She's a sociopath who tells pathological lies about almost everything.
Plus, the boss's wife is in a wheelchair, and I think audiences back then would assume that meant she couldn't perform sexually. (Modern audiences know otherwise).
A related question: why was Nancy in the boss's bedroom? Was it to steal the locket, engage in some hanky panky with the boss, or both?