An old-fashioned love story, penned Wilder with L.A.L. Diamond, the team that gave us Some Like It Hot, in which the guy (Jack Lemmon) gets his girl (the enchanting Shirley MacLaine) and they live happily ever after. It pleased Academy members no-end and they gave it Best Picture and Best Director Oscars and it regularly appears in lists of best comedies.
The film oscillates sharply and unsatisfactorily between near-slapstick and seriousness. The main problem is an implausible unawareness by C.C. Baxter (Lemmon) of his own immorality in his complicity in an arrangement in which he allows senior executives of the life insurance company at which he works to use his apartment for their extra-marital trysts in order to be looked favourably upon for promotion. When one of the trysts involves the girl (MacLaine) on whom he is keen, the worm turns; Although Wilder bring a certain European sophistication to bear this was Hollywood on the cusp of the 1960s and such awareness would have made it too cynical for perceived public taste, hence the low brow comedy and the way in which the conflict is resolved by the simple lesson that it is only when he asserts his virtue that C.C. gets the girl.
FYI: Wilder and Diamond visited related themes four years later with even less satisfactory results in Kiss Me, Stupid.