Common Sense Note
The only objectionable content in How to Marry a Millionaire is the premise, which is that the best thing a woman can do with her life is marry into money. It's a good opportunity to start a discussion about when in the past that was true (if ever), how things have changed, and whether more change is still needed. It's also a good opportunity to talk about how smoking in movies has changed over the years, what kind of influence it may have had on audiences, and how and why attitudes about smoking have changed. Otherwise, two or three brief kisses are shown, and there's a fair amount of social drinking.
Sexual
Content
Two or three brief kisses are shown.
Violence
Not applicable
Language
Not applicable
Social
Behavior
A character says early on that "marriage is the biggest thing you can do in your life." This premise is never disputed, nor is any alternative contemplated. It's no surprise that the main message from a Hollywood romance movie of this era is to follow your heart. As much as the woman thinks happiness in marriage requires using your head, she knows she won't truly be happy unless she's really in love with the man she marries.
Consumerism
Steinbock beer, Cadillac, Texaco, and Chrysler are mentioned once each, and a TWA airplane is shown.
Drugs / Tobacco /
Alcohol
As was typical of the era, the characters are shown drinking (champagne, rum, and beer) in social situations and smoking cigarettes and cigars frequently. Within the movie it's pretty matter of fact, but it's glamorized a bit by the mere fact that everyone looks good doing it.