Charlie has an unrequited crush on Alice; meanwhile, Doris has been desperately trying to win over Bob's affections. However, Alice and Bob are the ones who ultimately end up getting together.
When Alice and Bob finally go from Unresolved Sexual Tension to Official Couple, Charlie and Doris are left in the cold. Still, both of them have experienced the pain of heartbreak and unrequited love — so why not hook them up together? They may not have any initial attraction to each other, but they can always hang out and reminisce about their similar failed romances, and somewhere along the way, they might just find mutual love with each other like their former partners have.
While it's nice to see Charlie and Doris get a happy ending of their own, this device can very easily reek of red string puppetry and make viewers suspect that the creator just paired them off to permanently get them out of the main couple's way.
Differs from No Loves Intersect in that the leftover pairings are not immediately obvious and the involved people are initially just part of the Love Dodecahedron. Results from Conservation of Detail, since many viewers (and some writers simply wouldn't "buy" the spares getting over it by, say, dating outside the closed social circle of the cast to get away from the drama.
See Ship Mates for when the fandom does this in Fan Fic. Compare Sexual Karma, Lonely Together and Beta Couple.
There is a fifty-fifty chance that the Hero's Sidekick is in love with me. I'll find him a spunky, moderately-attractive tomboy type about his height, and steer them towards each other. If they quarrel, they're in love; if they hit it off, she loves him, but he's secretly unhappy with her and still loves me, and the Hero will need to send them off on a mission together.
Rizelmine's entire Love Dodecahedron gets resolved this way, down to one girl getting paired off with a dog that had molested her in an earlier episode.
Ginta and Arimi find love in Marmalade Boy in just this way. After chasing Miki and Yuu, they give up simultaneously on them and then fall in love with each other.
The same thing also happens to the American cast, more or less. In that case no one ends up with the person they originally wanted (or appeared to want).
The Kidou Tenshi Angelic Layer manga pairs up Tamayo and Oujirou, who had previously shown slight interest in Koutarou and Misaki, respectively. (The anime, on the other hand, flips the pairings, putting Tamayo with Koutarou and Oujirou with Misaki anyway.)
Technically, the anime doesn't have Oujirou WITH Misaki, so much as stalking her. Alongside Icchan's Stalking of Misaki's MOM.
Another case appears to have happened in xxxHOLiC, when it's revealed that despite the AnviliciousShip Teasing that has occurred between Watanuki and Doumekifrom even before the latter was formally introduced in the series, Doumeki ends up married to Kohane who also is in love with Watanuki.
In Ranma ½ fanfiction, this happens very often, mostly with Ship Mates type pairings. These writers mainly get their basis from the presence of Ship Tease for gags/storylines and short-lived moments of in-series Shipper on Deck: most of the characters in the Love Dodecahedron know that if their rival falls in love with somebody else, then whoever they want is sure to fall into their arms. This is why Ukyo promotes Ryoga with Akane, why Mousse promotes Ranma and Akane (and probably would support Ranma with Ukyo or Ryoga and Akane, if the ideas ever arose), and why Akane is quite willing to promote the idea of Ukyo and Ryoga or Shampoo and Mousse. Nabiki and Kuno are a popular fan couple due to a combination of some Ship Tease (a manga Filler story has them temporarily become enchanted with each other after being caught by a Love Potion version of the Umbrella of Togetherness, while an anime one has Kuno mistakenly being predicted as destined to marry Nabiki), though this invariably ends with Ship Sinking, and the fact that Kuno is Rich in Dollars, Poor in Sense and Nabiki's Money Fetish makes her easy to picture her hooking up with Kuno for his money.
The Fruits Basket manga does a pretty amazing job at this - two dozen characters all get paired off before the end.
The two exceptions among the main characters are Kagura and Momiji. Among the eligible minor-but-relevant characters, only four (Kimi, Saki's little brother Megumi, Naohito, and his unrequited crush Motoko) are left. Fanfic authors, start your engines.
Happens at the end of After War Gundam X: Garrod gets together with Tifa, then Sara and Jamil become an item... while Toniya and Witz get married, and Roybea and Ennil hook up. And while it may have been an Ass Pull, it was an awesomeAss Pull, as it was surprisingly well-written and kept up with the series's optimistic tone.
Lampshaded in Mahou Sensei Negima!. Natsumi reasons that she can't make a pactio (it requires kissing, but not necessarily coupledom) with Negi, because he's the protagonist and she's just "a side character". She then reasons that she could only do it with "the one guy who's in the same 'side-character' position as me" (Kotaro), with whom she has quite a bit of Will They or Won't They? subtext. They do, and they end up getting married.
Macademi Wasshoi has one of the weirder versions of this. At the end of the series, we have Takuto's harem still after him, though with Metallis being a huge supporter of Suzuka. Metallis' former sidekick George has been paired up with Macho Camp angel Hapshiel. It's a healthy, if somewhat bizarre, relationship.
In Code Geass, it is arguably implied that fan-favorite Jeremiah Gottwald aka Orange-kun surprisingly ends up with Anya. Then again, it's not really made clear. She could just have been unofficially adopted by him or something along those lines.
Some people assume they pair up (the age difference isn't as big as it looks), some assume he adopted her/they're Like Brother and Sister now, and a large faction of fanon has decided Jeremiah hooked up with and married Sayako offscreen and the two adopted Anya together.
It's more or less common to pair up Gino with Kallen in fanon, too.
Though it should be noted that this is based on the premise that Lelouch dies like he does in canon. Otherwise, there's little reason to pair them up together. It should be noted that in fanon "otherwise" is much more common.
Seems to be the main reason for Shugo Chara!Encore. Chapter 1: Utau/Kuukai. Chapter 2: Rima/Nagihiko. Chapter 3: Yaya/Kairi.
In Invincible, after Mark (the title character) starts dating Amber, his best friend William starts dating Mark's ally/secret crush Atom Eve. It sort of makes sense because they both know Mark's identity, but when Eve realizes how immature William is, they break up after a few issues. It looks like Mark and Eve will finally get together, if the book starts coming out on time...
And, yup, they're together all right.
A December 1993 FoxTrot storyline had Peter in conflict over whether or not he should take new character Mindy, who has a crush on him, to the Christmas dance, thus hurting the feelings of his girlfriend, Denise (who's taking a vacation to her grandmother's). In the end, though, Peter's problem is solved when Mindy falls in love with his friend Steve (and then mysteriously vanishes from the strip afterwards).
Film - Animated
At the end of Toy Story 2, we already know that Woody would be with Bo Peep, so it left out his sidekick Jessie. But of course, there's the perfectly available Buzz right there and Toy Story 3 expands on their relationship considerably.
In Gnomeo and Juliet, Juliet's father tries to set her up with Paris. Unlike in the play, he survives and winds up falling for Nanette, Juliet's friend (roughly equivalent to the Nurse).
In the wedding scene for Despicable Me 2, Silas Ramsbottom (Lucy's boss) and Natalie (Gru's "bad" date) are shown dancing together and actually enjoying each others' company.
Film - Live-Action
An early script for You've Got Mail has Kathleen (Meg Ryan) and Joe (Tom Hanks) trading partners by the end of the film. This was dropped by the time filming was done.
Many screwball comedies, from The Philadelphia Story (the reporter and his female assistant are told they should get together, when they've shown absolutely no interest in each other throughout the movie) to The Palm Beach Story (the couple considering a divorce decide to get back together, but tell their paramours they both have identical twins, leading to a triple marriage at the end).
Oddly enough in the musical version the assistant has a crush on him for the entirety of the play.
Shown absolutely no interest in each other? It's pretty clear that Mike and Liz are in a relationship in The Philadelphia Story.
Tracey: I don't mean to criticise, you probably have other interests outside your work.
Mike: None. (looks at Liz, scrambles to recompose) I mean—us—
Tracey: How sweet.
Done for laughs at the end of Baseketball. Coop ends up with his love interest Jenna, and Squeak embraces the possible transsexual he has been sharing looks with. Remer on the other hand looks despondent until he meets gazes with Yvette, a character he has had no interaction with throughout the movie. They immediately begin making out.
In Enchanted, leftovers Edward and Nancy get together after an uncertain amount of time passes. Since the two travel to Andalasia to get married (rather than in the "real" world), where the fairytale nature of the realm can make spontaneous love work it's quite probable that they literally live happily ever after.
Although in the novel, the pairing was actually set up quite nicely and built up pretty well in the background of everything else that was going on, the movie version of The Lord of the Rings makes the Faramir/Éowyn pairing seem like a version of this trope. Éowyn loses out on Aragorn and gets his "slightly inferior replacement" of sorts. It's a shame, too, because the imagery of the two recovering together in the Houses of Healing was one of the nicer images from the book, both Éowyn and Faramir got quite the Character Development out of their scenes, and Faramir's proposal to Éowyn is the closest thing the book has to an actual romantic speech. Whereas in the movie, the whole implied romance comes and goes in the space of a single reaction shot. There's more shown in the extended version, but still...
Saving Silverman parodies this; the protagonist marries his childhood sweetheart, and the evil Disposable Fiancée is paired off with his best friend, but then Jack Black's character (who has mentioned he might be gay) marries R. Lee Ermey (playing himself, as usual).
In High School Musical 3, all of the main cast is paired except for Ryan, the closest Disney will ever get to having an openly gay character, and Kelsi, who has been the source of a heated debate over whether or not Disney also put a lesbian in the film. So, naturally, Disney covers their butts from the many people who would have objected to having homosexual characters in a Disney film, and pairs them up. That said, all they do is sing a duet together, and have no other screen time together.
In the stage version, Kelsi is paired with Jack Scott (who doesn't appear in the films). This is done right at the end with no explanation. The two have about five seconds of dialogue.
In the musical Seven Brides for Seven Brothers, this is the premise from the beginning; 6 of the titular brothers, unhappy that the oldest of them is wed, kidnap 6 girls they like from the nearby town and try to Stockholm-seduce them over the winter.
Parodied, then played straight with a little justification in Mean Girls. The remainder of the Power Trio (one a gay guy, the other probably not a lesbian) have an Almost Kiss at the final dance, before being mutually disgusted and breaking apart. Then another minor character, who's actually shown an interest in the girl previously, finally gets his chance.
Happens in Old School with Frank The Tank and Heidi (Luke Wilson's swinger girlfriend from the beginning of the film). Granted, Frank and Heidi would probably be a pretty good couple.
Surprisingly averted in the romantic comedy He's Just Not That Into You. Three characters are newly single at the end, two of them by choice, and the narrator says words to the effect of "sometimes the best person for you is you," which means that being in a relationship isn't the be all end all of life, and that not being in one is sometimes the best route to take.
In She's The Man, the main characters' mean exes wind up together.
In I Give It A Year, each of the Alpha Couple has a rival love interest. The rivals date for a while, but the trope is subverted in the end, as the Alpha Couple finish up leaving each other for the rival suitors.
In ''Lord of the Rings," author J.R.R. Tolkien originally wrote Eowyn as the original love-interest for Aragorn, before he revised the story to include Arwen; so after he did so, Eowyn becomes rather hastily paired with Faramir, despite the two of them having absolutely no development together in the story except as patients in the same hospital.
I wouldn't say 'hastily'. They had quite a lot of a chapter dedicated to their growing relationship; the period of time from when they first meet to when they proclaim their love for each other presumably spans at least several weeks, and Faramir in particular has gotten to understand her very well.
Author J.K. Rowling of Harry Potter fame said in an interview that although she left open the possibility of a relationship between many characters such as Neville and Luna, she didn't explicitly state one in the wrap-up because it "felt too neat." That was also the main reason both of them ended up marrying a background character (Neville and Hannah Abbott) and a character that never appeared in any of the books (Luna and Rolf Scamander).
Inversion in OotP: the spares hook up a whole book before the Official Couple ( Cho Chang and Michael Corner and Harry and Ginny respectively.).
In Twilight, pretty much every character gets a Love Interest. Except Leah. It seems to tie into a theme of romance being the only important thing in a person (especially a woman)'s life. Even the baby gets betrothed! At a few days' old! To her mom's ex!
Charlie, a divorcee ends up dating recently widowed Sue Clearwater.
Edward himself is this at the beginning within his family, which is why they love Bella.
Averted and Lampshaded in The Tomorrow Series. Ellie mentions in the first book how the eight of them are in three different romantic relationships: Lee and Ellie, Kevin and Corrie and Homer and Fi, and then goes on to comment that it was too bad there wasn't any chance of Robyn and Chris getting together ("then we really could have had Perfect Partners").
As mentioned in the Film section, Éowyn/Faramir from Lord of the Rings (though to a much lesser degree). Apparently this happened because Tolkien originally intended for Éowyn to die fighting the Witch-King, but his wife thought that was too depressing, and that Éowyn should get a happy ending too.
Not quite: he originally intended her to marry Aragorn, then realized that wouldn't work and thought he might have to kill her off. Then Faramir popped up out of his subconscious....
In the Belgariad, this ends up happening to many of the supporting characters, such as Silk with Velvet, Zakath with Cyradis, and even Beldin with Vella. In fact, several of these characters aren't even mentioned until the second quintet, which suggests that the characters were created specifically for this trope.
Justified in that The Destiny is a huge Shipper on Deck. Polgara remarks that people who aid Destiny will be rewarded by finding happy love. At no point does anyone entertain the notion of being happy alone.
Beldin is quite happy alone. Belgarath also spend lots of time wandering the earth or doing research in his tower with little to no interaction with the outside world and liked it this way. But they are happier when Destiny-shipped.
In Agatha Christie's Appointment With Death, Carol Boynton and Jefferson Cope get paired up in the epilogue. This probably isn't all that unlikely, but it comes out of nowhere nevertheless.
Generally subverted in P. G. Wodehouse's books (Blandings Castle, Jeeves and Wooster, etc), in which a typical plot might go as follows: A loves B, and C loves D. But just before the book starts, A and B break up over something, and A, seeking to show he's not heartbroken (though he is) proposes to D, who is temporarily convinced that C is a complete bastard. Then everything gets disentangled. Subverted in that the eventual pairings are set up quite early on in the book. This formula is then livened up by wonderfully eccentric characters, hilarious plot twists, and fabulously funny writing.
The Fionavar Tapestry series of books begins with five protagonists transported from Canada to the magical world of Fionavar: over the course of the trilogy, two die and one decides to stay in Fionavar after hooking up with a local woman. The remaining two decide to return to Canada, and on the last page they decide to go on a date, with no particular buildup to this in the preceding 700+ pages.
Orson Scott Card seems to be a fan of this in general. He ends the Ender's Game series in Children Of The Mind with a double marriage that seems to serve little point but to pair up all the remaining single characters of young adult age, among them an embodied fragment of another character's psyche and the recently created biological avatar of the future-internet's artificial intelligence.
Nicely averted in Jennifer Crusie's Bet Me. Despite the main couple and many of the side characters hooking up, Liza remains with temporary boyfriends by the end of the book.
Depending on which version of the King Arthur myth you read, Sir Gareth either marries his Distressed Damsel Lyonesse or his Damsel Errant Lynette. Either way, his brother Sir Gaheris marries the other one.
Averted in Betsy-Tacy. Multiple couples and pairings are suggested or named throughout the high school books, but only four of those couples ultimately marry. All other characters marry someone they met after high school.
Throughout Rachel Hawkins' Hex Hall series, Sophie has a Love Triangle going on with Archer Cross and Cal. Further complicating things is the fact that the ghost of Archer's ex-girlfriend Elodie is magically bound to Sophie. In the final book, Spell Bound, Cal decides to sacrifice his life in order for Sophie to live, knowing she is in love with Archer. Afterwards, Elodie's ghost asks Sophie to unbind them so that she can stay with Cal's ghost.
Conspiciously averted in The Quest of the Unaligned. Not only does the story end with the Alpha Couple (Alaric and Laeshana) formally getting engaged, Word of God reveals that Gratelle later got engaged to a ruahk noble somewhere in the south and Nahruahn is too young to get married for another few years.
Swedish writer Simona Ahrnstedt does this in her debut novel Överenskommelser, when Lily and Alexandre suddenly hook up.
Live Action TV
In Smallville, after Clark Kent and Lois Lane finally admit their romantic feelings and UST for one another, and after Zod and Tess start exploring their Foe Yaywhich later evolves into Dating Catwoman, and because a large contingent of Chloe fans had been calling for Chloe/Ollie since Season 6 (often saying "Chloe deserves to have her own superhero" or "Chloe deserves to have her own billionaire" in comparison to the previous Clana, Lexana, and Lollie relationships) the producers finally acquiesced to the fan campaigns, and put Oliver and Chloe together as Friends with Benefits, and then later as a Battle Couple.
Parodied/exaggerated in Friends. Ross’s doppelganger Russ, newly dumped by Rachel, is saying goodbye to the gang. Julie, the woman Ross broke up with to be with Rachel, turns up. Russ and Julie look into each other's eyes, and in mere seconds are completely in love.
Also in Friends, Joey comments to Phoebe that "Ross and Rachel are together, Chandler and Monica are getting married, maybe you and I should...". She replies that they do, "all in good time".
Joey actually averts this. By the end of the series, he's the only friend not in a serious relationship.
LOST: Jack and Kate get off the Island and hook up (for a while), leaving behind Kate's other love interest, Sawyer, and Jack's other love interest, Juliet. Sawyer and Juliet eventually get together, but it's a testament to the acting ability of Josh Holloway and Elizabeth Mitchell that the Sawyer/Juliet relationship comes out of nowhere (unless you'd been brushing up on this trope) and yet many viewers felt they were more convincing, more dramatic and way less annoying than the Jack/Kate relationship, which had been around from the pilot episode.
Parodied on an episode of the sitcom WORKING!!, where after a ban on inter-office relationships is lifted, everyone quickly pairs off in order to release the sexual tension that had been building. The Butt Monkey is too slow, and the only one left is a Little Old Lady.
The Doctor Who story The End of Time shows Martha Jones and Mickey Smith being married, even though Martha was previously (supposedly happily) engaged to someone else and their interaction during the show was minimal. Word of God states that her honeymoon mentioned in Torchwood was actually to Mickey, and both characters were initially intended to appear before Noel Clarke and Freema Agyeman were unavailable.
In Scrubs, after J.D. and Elliot get together for good, their exes Kim and Shaun also become a couple.
Earlier, Season 3's finale played with this by having Sean drive Danni (JD's girl of the season) home.
Spaced hints at this in the second series, with Mike and Marsha. While their interaction throughout the series is easily open to interpretation, their last scenes in the final episode give at least some evidence to a potential relationship.
Fans of Degrassi The Next Generation are fond of this, pairing (for instance) Emma with Jay so as not to interfere with Ellie/Sean. (Emma is paired with Sean. Ellie is not paired with Jay.) Similarly, practically all Spinner/Manny shipping is to stop anything from happening between Craig and Manny. Craig/Manny shippers are conversely fond of Jimmy/Ashley and Sean/Ashley, while Emma/Sean shippers are fond of Craig/Ellie.
In series example. At the end of Season 9, long standing couple Jay/Manny had their best friends (Spinner and Emma) get married. Some fans were not pleased by this. In that it ruined the chances of Emma/Sean and broke up fairly long lasting Spinner/Jane.
A better example would be Jimmy/Hazel. Spinner and Jay aren't exactly best buds. It's just that Jimmy was angry at Spinner for the whole paint and feathers incident.note Immediately afterward, Rick went home, brought a gun to school, and the rest is history. With Rick dead, Jimmy blamed Spinner. At the same time, Sean had lost his mind after killing Rick.
In The X-Files, Dogget and Reyes, the two agents that replace Mulder and Scully, are romantically involved during their one season onscreen. It would have been interesting to see where that relationship had gone, had the show's ratings not been so low and the show cancelled.
It was obvious from the onset that Reyes was meant to be Doggett's love interest. Chris Carter said that Doggett was not meant to replace Mulder or be a love interest for Scully. So it seems Reyes, while mostly being brought on to replace Scully on The X-Files, also had the added bonus of placating outraged MSR shippers.
Glee pairs Brittany and Artie as well as Sam and Mercedes for seemingly no other reason than this trope.
Some Castle fans view the Espositio/Lanie pairing this way, since Castle/Beckett is the Official Couple and Detective Ryan is engaged. However if you watch closely to first and second season episodes, Esposito is flirting with Lanie.
Lampshaded on Home Improvement: Tim points out Jill's attempts to Pair the Spares, and Jill responds, in an angry tone, "Because I want everyone to be as happy as we are."
In Our Day Out, two students of opposite sexes each have a crush on one-half of a teacher couple. One of the teacher couple encourages the students to get together, and they do.
Padre Coraje, being a soap opera, ends up with most characters either paired up or dead, but the most egregious example is Mercedes and Horacio, who hook up in the very end of the last episode, and it is even mentioned that what brought them together was having spent their lives obsessing over half of the main couple. The funniest thing is, being Unlucky Childhood Friend and Bad Guy Jr., they'd had lots of interaction, and it was never romantic.
The last episode of the first season of The IT Crowd ends with three Bedmate Reveals. The first two are already the inverse of what we might expect, and the third involves the only other two recurring characters, Richmond and Denholm.
In one episode of Stargate Universe a failed attempt to get back to Earth leaves the characters stranded on an unpopulated planet centuries in the past. With no way back to Earth or their time, the characters resign themselves to spending the rest of their lives on the planet and quickly start pairing off and getting married. After all the obvious couples are paired up, the left over characters start pairing up amongst themselves which results in some Crack Pairings. This is justified by the situation since the relationship pool is very small and the only alternative for most of them is to spend the rest of their lives alone. In contrast, an alternate version of the characters who avoided being stranded in the past, avoids this trope because most of them still have a hope of returning home and thus do not see the need to jump into relationships.
Taken to a science by Gilbert and Sullivan. They do this in nearly every one of their plays. In the final number, all the pairs are established, and the crowds pair off as well.
In The Sorcerer, they go so far as to pair somebody off with the local Notary, who doesn't even get a name.
Of particular note is Patience. Attempts to Pair the Spares are the basis of an entire musical number. No matter which way the couples are made, there is always one man left over.
The final lines of the show: "Each of us will wed the other, / Nobody be Bunthorne's bride!" Given that the operetta's titled Patience, or Bunthorne's Bride, this is a pretty major subversion.
Convincing a character that Pair the Spares really is the way to go and she'll be a lot happier that way is the basis of the entire finale of The Mikado, including the immortal lyric: "You've a very good bargain in me."
Parodied in The Pirate Movie, where Mabel, after being told she can't marry until her older sisters have married, freezes her dream and pairs everybody else off. Including, since there are more pirates than sisters, pairing two of the male pirates together.
Subverted in The Yeomen of the Guard, where everyone ends up with the wrong person, and poor Jack Point is left out to dry.
At the end of Ruddigore, Rose goes back to Robin, so Richard decides to marry one of the bridesmaids instead.
Ruddigore is probably the play that most rigorously enforces this trope—even the haunted portraits of the barons of Ruddigore get married (to more bridesmaids!) at the end.
In some shows the pairs aren't explicitly stated in the script, but that generally won't stop most theater companies from pairing people up anyway. There are only two pairings at the end of The Mikado: The romantic lead Yum-yum and Nanki-poo, and the plot obstacles Katisha and Ko-ko. But typical amateur productions also pair up most or all of the other leads, and the entire men's chorus of Gentlemen of Japan with the women's chorus of Schoolgirls, for the closing number.
Not really part of the story itself, but in adapting La Bohème into RENT, this is done. In Boheme, the musician Schaunard and the philosopher Colline are happily single secondary characters (and make plenty of wry comments about their friends Rodolfo and Marcello, and their relationships). Their analogues in RENT, Angel Schaunard and Collins, are a couple.
In Wicked, Galinda's attempt to pair off her Stalker with a Crush Boq with Nessa, Elphaba's unbalanced sister, proves one of the most disastrous on fictional record.
Oklahoma!! has Gertie Cummings, who flirts with Curly in the first scene, and Ali Hakim, the threat to the Beta Couple of Will and Ado Annie, married before the final scene by means of a Shotgun Wedding.
Directly invoked in the lyrics of the Act II Finale of Spamalot, where the male and female chorus members pair off for a big group wedding.
In Cole Porter's musical Anything Goes, the characters Hope and Billy knew they were a perfect match before the play opens, but after being apart for a while, Hope gets engaged to a stuck-up wealthy Englishman named Evelyn, and Billy is propositioned by his longtime friend, a sassy nightclub evangelist named Reno. In the end, Evelyn is revealed to have gypsy ancestry and be hiding a spontaneous wild side. He marries Reno, Billy marries Hope, and Billy's boss marries Hope's mother.
In Oscar Wilde's The Importance of Being Earnest, all the crazy hijinks due to all the "Bunburying" get sorted out and the young people are satisfied by the end. So of course, the PRIEST and the NANNY embrace passionately too. (He's an Anglican priest, though—not Catholic—so he's allowed to marry. And they had been flirting all through act II, though without much success.)
In Kander and Ebb's Musical, Curtains, after Bobby finds his love, Georgia, is back with her ex-husband, he starts a romance with Bambi, the last single female role.
"No sooner met, but they looked; no sooner looked, but they loved; no sooner loved, but they sighed; no sooner sighed, but they asked one another the reason; no sooner knew the reason but they sought the remedy." —Rosalind
Also, to a lesser extent, in Measure for Measure. Vincentio and Isabella are paired off together, though Isabella had intentions of becoming a nun and he's obviously way too old for her. There is also Lucio, and Random Prostitute A.
Subverted in Sheridan's The Rivals, in which all the major characters but two are already paired by the end as part of the story. This leads another character to suggest that spares Sir Lucius O'Trigger and Mrs. Malaprop pair up, but Sir Lucius responds with disdain.
Fire Emblem: Genealogy of Holy War has Badass Bookworm Azel trying to woo over White Magician Girl Edin, while his childhood friend and Rebellious Princess Tiltyu chases after the Priest Claude. Depending on the players' actions, they may succeed their wooing. But should they fail... both of them can hook up together. And they're actually predestined, meaning they can be hooked up very easily due to game mechanics.
Since the first half of the game revolves around making sure that all your female characters are paired up with a husband, the gamer can actively engage in this trope if he/she realizes that they did not pair up somebody yet and all the "normal" options are taken.
Some of the Harvest Moon games (especially the Mineral Town ones) fall into this trope. After you've chosen your bride, your romantic rivals will often end up marrying their crushes (e.g. if you decide not to pursue Elli, then the Doctor gets her, and if you don't flirt with Ann, then she winds up with Cliff) a few weeks after you have your ceremony.
Subverted: If you don't choose Cliff for a certain event, he will leave for good and Ann will remain single.
And if you don't see their 2nd heart event before that event they still remain single (but Cliff doesn't leave).
Flame and Ember from Spyro: A Hero's Tail are almost always shipped together, despite the two never showing interest in each other, and Ember's crazy obsession with Spyro. This is mainly because Spyro gains a canon love interest, Cynder, in The Legend of Spyro reboot series, even though Flame and Ember don't exist in that continuity.
If you show no interest in the human love interest (Ashley if you're male, Kaidan if you're female) in Mass Effect 1, they will show hints of mutual attraction until you have to leave one to die.
In Mass Effect 3, if you did not romance either Tali or Garrus over the course of the game, they will have dialogue between one another that sounds increasingly flirty. Eventually you'll catch them at Garrus' station embracing one another. Apparently BioWare decided the dextro-squaddies/two fan favourites of the franchise might as well date each other at the end given the option. Don't worry Talimancers and Garrus fangirls (or fanboys), if either of them are already in a relationship with Shepard, they'll just remain good friends.
In the Citadel DLC for 3, providing Ashley is still alive, she can potentially hook up with Vega.
Also in Citadel, Shepard can suggest that Jack and Miranda pair off. They are notamused.
Yet again from Citadel, Zaeed's attempts to do this with Samara are soundly shut down.
Mostly nonromantic example - in Hatoful Boyfriend, at the end of the Bad Boys' Love route, the characters who were most significant in each others' plotlines are shown talking to each other - brothers Sakuya and Yuuya, Foe Yay couple Kazuaki and Shuu (who have a relationship to which "attempting to apply ethical guidelines is completely futile"), and Victorious Childhood Friend Ryouta with Hiyoko. San and Anghel, who barely interact, are shown together too, simply because they're both the two characters too weird to coexist happily with anyone else (Anghel is either Longing for Fictionland to the point of madness, a Reality Warper who can't perceive the same reality as anyone else, or a full-blown Talkative Loon with extremely vivid Hallucinationsdepending on interpretation; San is a throwback to before birds were fully uplifted and thus is The Ditz. The ending portrays them as getting along due to Anghel being too crazy to notice San's stupidity and San being too stupid to notice that Anghel is crazy.
This seems to be the basis with Reyn and Sharla in Xenoblade, given that Reyn is the first guy to join the party and Sharla the second girl to be introduced, and that the trio works together exclusively for the Bionis Knee section of the game, their bonding over the rest of the game feels almost expected.
Sort of done in Toejam And Earl: Panic on Funkotron in the Golden Ending. At the end of the game, Leshawna hooks up with either Toejam or Earl depending on who the player is controlling when they finish the game. If it's ended in 2-player co-op mode, then she gets together with Toejam, while Earl is introduced to Leshawna's never-before-seen identical twin sister.
Used non-romantically, Itsuki and Pontiff Xavi are made rivals in the first Sengoku Basara, for no other apparent reason.
In Boy Meets Boy, Skids vents his frustration about his unrequited feelings for Harley out on Tybalt, the ex-boyfriend of Mikhael, Harley's current boyfriend. To make things even more complicated, Tybalt has also tried to seduce Harley and initially views Skids' lingering attraction to him as an obstacle. Long story short, the two become close friends and share a kiss near the end of the strip's run.
Khaos Komix has an interesting aversion in which Mark and Amber, while dating one another, get their best friends to go on a double date with them. The twist is that Mark and Amber break up that very night to be with their respective 'spares' in the end.
The goal in the "Serious Business" story arc in the Insecticomics is to pair the spares. All of them, even the ones who weren't unpaired to begin with, and in as many combinations as possible.
In-story example, from Girl Genius: As the Heterodyne Boys have been Shrouded in Myth, since Bill married Lucrezia shortly before their disappearance, his brother Barry was given the stock character of “The High Priestess” for a love interest in most present day dramatizations of their adventures.
Sonichu takes this to a major extreme. At first, the only pairing was the titular character and Rosechu. However, by issue 9, Episode 19, Chris has paired just about everyone of his creations with a girl and remedies the last one, Magi-Chan, in the next episode. He... just doesn't like anyone being alone.
Toward the end of Fans! Book 5 (the strip's original Grand Finale, before it was revived), Tim ends up married to Julia. In a conversation between Guthrie and Meighan, it is more or less revealed that Meighan had hired Julia (an old friend of hers from college) for the express purpose of setting her up with Tim.
Code Lyoko: While they don't hook up, Yumi's and Ulrich's Romantic False Leads, Sissi and William, have a heart-to-heart chat at the pool commiserating about their unrequited crushes, realizing they both desperately want the same thing: for these Just Friends to get over each other.
Sissi and Odd unknowingly dated online. Perfect plot wasted.
In ReBoot, Mouse was first brought in as a former flame to Bob, making Dot jealous. In Season 3, during their travels, Matrix and AndrAIa encounter Ray, who the former instantly pegs as a rival for her affections. Naturally, the two end up together.
Kim Possible: After the Kim and Ron hookup in The Movie, they started pairing spares. Bonnie got matched with Señor Senior Junior in a late Season 4 episode, and in the Graduation Grand Finale episode they paired Felix (and his cool wheelchair) with Zita Flores (who hadn't been seen for about 70 episodes), Drakken and Shego was implied during that finale and Wordof God confirmed them as hooking up. A stand alone episode involving nerdy Cousin Larry also had an implication that he was going to get involved with a friend of his. This basically left only Monique and Wade as unattached, and probably only because of their age difference.
On The Simpsons, at the end of the episode parodying the Big Brothers institution, Homer's Little Brother and Bart's Big Brother seem to be left out in the cold... until Bart points out that they would both do well together.
Before Bart matches them up, they actually spend a few moments bemoaning their situation in a way that, if they were actually paying attention, would indicate that they were perfect for each other — and then cheerfully bid each other farewell.
Parodied in the episode "The Canine Mutiny", in which Bart obtains an extremely well-trained rough collie named Laddie, and gives up Santa's Little Helper, who ends up living with a lonely blind man. At the end, when Bart manages to get SLH back, Laddie shows up (now working as a police dog) and appears to take an instant liking to the blind man, making it look like we're in for a heartwarming "Pair The Spares" conclusion. Turns out, Laddie is merely fulfilling his duties as a drug sniffing dog...
A recent episode depicts Marge and Homer five years in the past, almost cheating on each other at the same time at the same motel. When they run into each other each tries to hide this fact, and Homer's almost-mistress winds up locked in a box with Marge's almost-lover. Back in the present, the two are happily married with a daughter.
In Tiny Toon Adventures, Hamton J. Pig and Fifi la Fume occasionally had romantic interests with each other. Mostly because they're both the third persons in their 3-man teams, with Buster/Babs and Plucky/Shirley
In the wake of the wedding of Prince William and Kate Middleton, even the legitimate media is gleefully speculating about William's younger brother Prince Harry possibly getting together with Kate's younger sister Pippa Middleton, despite the fact that they're both seriously seeing other people.
When Nicole Ritchie started dating Joel Madden, Nicole's best friend Paris Hilton started dating Joel's identical twin Benji. Though unlike the former, they broke up.