Honeymoon Deferred (movie, 1940)

Edmund Lowe plays an insurance investigator who interrupts his honeymoon to look into the case of a murder, which could also be a suicide, in which case his company won't have to pay the victim's contract. His wife, played by Margaret Lindsay, insists on following him around, not only to help him solve the case, but to make sure he doesn't get too friendly with any members of the opposite sex, either.