Disposable Love Interest

"It never could be love That's how it hadda' be Her name reminds me of Female anatomy"

- James Bond theme, with added lyrics

The mysterious vanishing of a hero's established love interest between the first movie and the sequel. Related to the Cartwright Curse, but this is where what happened to her isn't mentioned, and is never referenced again. They can't have the hero settle down because Status Quo Is God. On the other hand, they can't make the hero look like a heel by spelling out why their relationships always fail, so the situation becomes the Elephant in the Living Room.

Basically, the girls aren't put into the movies to be characters or interesting, but merely so that the main character can go through the motions of a fresh Token Romance in every single sequel.

Related to Girl of the Week. See also Disposable Woman. Contrast with Disposable Fiancé, who exists only to be disposed of.

Films - Live Action

 * Basically, every James Bond movie ever produced.
 * One of the James Bond books handwaves this by having the female character in Diamonds Are Forever break-up with James and marry a Marine stationed at the US Embassy in London.
 * You can understand his commitment-phobia though, considering the one time he marries someone, she dies at the end of the movie.
 * Given the depth of most of these relationships and Bond's general attitude to women, it actually makes perfect sense to assume the relationships all fell apart shortly after the film ended.
 * Every one of the 1990s Batman movies has a new girl for the Batmeister who will only get mentioned if she's lucky. Catwoman probably eats them.
 * Rachel Dawes, at least, got an It's Not You, It's My Enemies speech in Batman Begins, and "she" got to give it back to Bruce Wayne in The Dark Knight.
 * Indiana Jones
 * Until Indiana Jones and the Kingdom of the Crystal Skull, which sees the return of the marvelous Marian Ravenwood.
 * Spoofed in the second Austin Powers movie, where his love interest from the first movie turns out to be a robot that explodes. Played straight in the third one.
 * The Karate Kid film series goes through one love interest each movie.
 * At the end of Men in Black, Agent J's love interest becomes a member of MIB herself, and J's new partner. Cue Men In Black II, where she's apparently gone back to her old job, and J is having trouble keeping a partner for very long.
 * In-story, it was because L couldn't stand the pressures of working as an MIB and missed the solitude of the city morgue. On a mets level, it was because Linda Fiorentino is apparently a nightmare to work with and nobody who did it for the first movie wanted to do it again in the sequel.
 * Mission Impossible 2 closes with Ethan Hunt and Nyah Hall living happily ever after. M:I-3 opens with Hunt marrying a different woman, and Nyah is never spoken of again.

Literature

 * You could make an argument for the inexplicable (in-story) disappearance of Fenchurch toward the beginning of Mostly Harmless.
 * The radio series makes this a lot clearer.
 * Robert Langdon has Vittoria Vetra in his first book, Sophie Neveu in his second, and Vittoria a completely different hot science chick in his third. There's a brief Hand Wave towards the fact that he's no longer with Vittoria in The Da Vinci Code, but nothing else. Although that's the least of the series' logic problems, to be honest.
 * While perhaps not the oldest example, the Victorian novelist Anthony Trollope did this on occasion. The husband of the female protagonist of The Warden is dead by the beginning of Barchester Towers so that she is open for marriage again. The wife of the protagonist of Phineas Finn has Died In Childbirth by the beginning of the sequel, Phineas Redux.
 * Amy and Kayra in the Castaways of the Flying Dutchman books by Brian Jacques.
 * Name one of Luke Skywalker's girlfriends. Mara Jade is the only one that doesn't quallify for this trope.
 * Not anymore, she isn't.

Live Action TV

 * Kate Warner's breakup with Jack Bauer between seasons 2 and 3 of 24 got a Hand Wave that didn't explain much of anything. Considering that Jack's other love interests were killed by his ex-lover-cum-spy (who in turn Jack killed by his own hand), taken down by stray bullets in a gunfight, or brainwashed by the Chinese government, Kate got off easy.

Video Games

 * Stretched almost to the point of Deconstruction by Metal Gear Solid and its sequel. Snake ends up happily with the girl, Meryl, but by the time of the second game their relationship has not only failed without explanation but Snake's now actually living with a man, who seems more compatible with him than she was. It's straighter than it sounds...but not much.

Western Animation

 * Subverted in an episode of Futurama. Bender and the disembodied head of Lucy Liu fall in love at the end of one episode and vow they'll marry. This relationship is never mentioned again... except in one episode that reveals she's been living in his chest cavity all along.