''Unfaithfully Yours'' is a 1948 film from Creator/TwentiethCenturyFox, written and directed by Creator/PrestonSturges, and starring Creator/RexHarrison and Creator/LindaDarnell, with a remake in 1984 starring Creator/DudleyMoore and Creator/NastassjaKinski.

Renowned conductor Sir Alfred De Carter has been HappilyMarried to his wife, Daphne, for a number of years. But when he arrives home from a trip, he receives distressing news. His brother-in-law misunderstood when Alfred asked him to keep an eye on Daphne, and hired a private detective to watch her. Then it turned out the detective actually did find evidence that Daphne might be having an affair, due to seeing her enter and leave the room of Anthony Windborn, Alfred's secretary.

Distressed over this apparent betrayal, Alfred has differing fantasies over what to do as he conducts a concert, each fueled by the three extremely different musical pieces, which he conducts during the performance. The first fantasy is about murdering Daphne and framing Winborn, played to Rossini's ''Semiramide'' overture. The second about forgiving Daphne and letting her be with Windborn, to the overture to Music/RichardWagner's ''Theatre/{{Tannhaeuser}}''. The third about confronting them over their affair, to Music/PyotrIlyichTchaikovsky's ''Theatre/RomeoAndJuliet''-fantasy overture.

And then he tries implementing these fantasies for real.

This film could have been many things with its premise, but it's actually a dark comedy about how Alfred deals with his feelings. This is suspected to be reason it didn't do well at first, but grew in reputation with audiences used to such subject matter.

Another possible reason the film did not do well was the suicide of Carole Landis, a film actress and lover of Rex Harrison. Landis took a fatal overdose of sleeping pills after Harrison refused to leave his wife for her. ''Unfaithfully Yours''--a comedy in which Harrison imagines murdering his wife--came out only four months after Landis's suicide and the ensuing scandal.
!!Contains Examples Of:
* BlackComedy: While mild by today's standards, it might have been too much for TheForties.
* CannotSpitItOut
* CrazyJealousGuy
* DreamSue: In Alfred's daydreams, everything goes perfectly for him. [[spoiler:He successfully kills his wife and frames Tony; he martyrs himself in the name of love in the best Humphrey-Bogart-in-''{{Casablanca}}'' fashion; and he manfully dies in a game of Russian Roulette after dramatically confronting the cheaters with their crime.]] However, reality proves…somewhat different.
** Certain things work in the fantasy sequences that wouldn't at all in reality. For example, speeding up a phonograph recording of Alfred's own voice is sufficient to make it sound exactly like that of his wife. Though he was never able to make the machine speed up his voice in real life afterward, he wouldn't have sounded like his wife even if he had; he'd have sounded like one of [[WesternAnimation/AlvinAndTheChipmunks the Chipmunks]].
* FantasySequence: Alfred gets three of them, set to three different pieces of music. However, it doesn't go quite so smoothly when he tries to carry these fantasies out in reality.
* HilarityEnsues: Alfred trying to fulfill the first fantasy.
* IJustWantMyBelovedToBeHappy: The second fantasy.
* ItWorksItself: The claim for the instructions of the recorder.
* LoveTriangle: Or at least it seemed to be one.
* MentalStory: The fantasy sequences.
* MistakenForCheating: Daphne.
* OperaGloves: Daphne wears a particularly pretty, sequined pair to accompany her black strapless gown throughout almost the entire second half of the movie.
* ThePerfectCrime: The first fantasy.
* PimpedOutDress: Daphne's dress for the concert, and the dress "with [[FluffyFashionFeathers the plumes]] at the hips".
* PrettyInMink: Several, with Daphne even asking her sister what fur she would be wearing so Daphne [[DefiedTrope wouldn't]] end up [[DressesTheSame wearing an identical one]].
* TheRemake: The 1984 version. It was [[WhatCouldHaveBeen originally going]] to star Creator/PeterSellers, but his death in 1980 scuppered that.
* RuleOfThree: The different fantasies Alfred has.
** When Alfred is trying to get the recording machine to work in "real life," as he fiddles with the controls, the machine's arm twice lifts the disc off and drops it to the side of the machine. The third time, when Alfred reaches out his hand to catch the disc, the machine instead ''flips it over and puts it back on the spindle.''
* RussianRoulette: The third fantasy has Alfred force Windborn to play this with him.
** Subverted when he tries to actually do it with Daphne, and she gets confused over which game.
--->"My father and I played it all the time."
* ScrewballComedy
* {{Socialite}}: Daphne and her sister.
* YourCheatingHeart: The driving force of the plot. [[spoiler:But it turned out Daphne's sister slept with Windborn, and Daphne trying to help her sister sneak out of the room made it look like it was her.]]