Dead Sparks

Alice and Bob went through the whole Romance Arc. They started out as Just Friends. They developed some Unresolved Sexual Tension. Then the two shared their First Kiss and it was magical. Alice and Bob were on the road to Happily Ever After (or at least Happily Married).

But that was all a long time ago.

Now they're the couple who sit silently across from each other at the restaurant, eating perfunctory dinners. The sex is rote (assuming they even have sex anymore). Alice finds herself noticing that Chris is looking especially good lately and wonders what it would be like to kiss him. All the little quirks Bob found endearing about Alice now drive him up the wall.

Maybe there was passion here once, but now there's nothing but Dead Sparks.

Examples of Dead Sparks include:

Film

In Eternal Sunshine of the Spotless Mind, we first meet Joel and Clem when they are at the Dead Sparks stage of the relationship. The rest of the movie is about how they ignited those sparks in the first place and ends with the hope that they could be reignited.
In Unbreakable, the Dunns' marriage is like this. The affair that David had certainly didn't help.
In Ordinary People (both the book and the film), the death of their oldest son pushes Beth and Calvin to this point. It doesn't end well — she walks out at the end.
Six Degrees of Separation: John and Louisa Kittredge's relationship is Dead Sparks throughout.
In The Sixth Sense, we're led to believe that Malcolm and his wife have this problem. Subverted of course, with The Reveal: he's dead, and she's in mourning.
One of the oldest and most concise examples can be found in Citizen Kane, where one scene tracks the progression of Kane's relationship with his wife by looking at their breakfast discourse over the years.
In Mr. and Mrs. Smith the eponymous characters' marriage has hit this stage. But it seems that trying to kill each other creates enough sparks to revitalise the relationship.
In Date Night Steve Carrell and Tina Fey play a married couple who have lost the spark. But not to worry! Nothing a few spy-related adventures can't fix!

Literature

Margaret Peterson Haddix's Just Ella: The premise is that this is experienced by Cinderella sometime following her marriage to Prince Charming.

Live Action TV

In Peep Show, this is what happens after Mark finally gets together with Sophie. It doesn't stop him from marrying her (or, at least, from calling off the ceremony).

Music

This theme is covered in a lot of Country Music songs:
- Tanya Tucker's "Love Me Like You Used To",
- George Strait's "I Know She Still Loves Me",
- Reba McEntire's "Somebody Should Leave".
- Tracy Byrd's "I Wanna Feel That Way Again" is right there in the title.
- As is the Brad Paisley-Carrie Underwood duet "Remind Me".
Rupert Holmes' "Escape, (the Piña Colada Song)," starts out this way:

I was tired of my lady, we'd been together too long.
Like a worn-out recording, of a favorite song.

Carly Simon's "That's the Way I've Always Heard It Should Be" describes every marriage the narrator has ever seen as having turned out like this.
Simon and Garfunkel's "The Dangling Conversation" and "Overs".
Gordon Lightfoot's "If You Could Read My Mind".

Western Animation

In the first episode of Family Guy after its UnCancellation, Lois starts calling out male celebrities' names during sex instead of Peter's. He fears that it's the first step toward a life where all they do is sit across from the table from each other talking about Special K cereal.