WoW! I just purchased Holiday Affair with Robert Mitchum, Janet Leigh, and Wendell Corey. This movie was released in 1949. If you like Mitchum then you'll like this movie. It is really a good movie.
The plot of the movie:
Just before Christmas, department store clerk Steve Mason (Mitchum) meets big spending customer Connie Ennis (Leigh), really a commercial spy. He unmasks her but lets her go, which gets him fired. They end up on a date, which doesn't sit well with Connie's steady suitor, Carl Davis (Corey), but delights her son Timmy (Grodon Gebert), who doesn't want Carl for a step-dad. Standard (if sweet) romantic complications follow.
Cheers