—Raven to Beast Boy just before he totally ruins the moment, Teen Titans
It's really going to happen this time. They are about to share with each other their feelings after years of keeping them hidden. They come closer together and look into each other's eyes; there has never been a moment so perfect. The stars are aligned, the moon is full and one of them says, "I've never had the courage to tell you this before..."
Then her brother walks into the room, asking if she wants pepperoni or ham on her pizza. Or his/her best friend walks through the door, wanting to talk to them, which sometimes may be an emergency. Or the house phone rings or one of their cellphones ring, ruining the moment. "Ugh!" is their reply, echoed by all of the fans. Whatever was there has been shot down dead. They lost the spirit of the moment and it will likely be a long time before they can get it back. After witnessing their frustrated anger, the brother then asks, "Is this a bad time?"
The Moment Killer is the bane of all shippers, and eternally frustrates those who will find any reason to hook up a favorite pairing. The moment is far most commonly romantic in nature, but covers the instances whenever there is a possibility of a relationship upgrade or change, including going from enemy to ally or getting that coveted "Well Done, Son."
The exact nature of the killer can come under several varieties:
Random Accident: The killer is something mundane, so that the frustration is at its highest because the important moment is destroyed by something unimportant. (The pizza example above.)
Plot Progression: Something too important to ignore interrupts the moment, but it doesn't make the moment killing any less painful. (Aliens attack.)
Fatal Fumble: One of the individuals involved ends up being their own moment killer due to miscommunication, poor choice of words, or just a brief hesitation that ruins the magic. ("Hahaha, you're joking, right?")
Deliberate Destruction: A third party intentionally spoils the moment for reasons of their own; often a jealous rival or Overprotective Dad. Also called "the cockblocker." ("You guys aren't doing anything funny in there, are you?")
More than one beer commercial has used the idea of a Moment Killer, usually demonstrating how the advertised beer will aid in thwarting him.
Anime & Manga
Detective Conan: A running gag in the series is whenever Takagi and Sato tries to kiss, someone comes in and stop them just at the moment they're about to.
Planetes: Tanabe and Sempai are back on Earth, visiting his parents, they end up on the beach at sunset when Tanabe stumbles and create by accident the favorable position for a kiss... a frigging rocket launched by Hachimaki's brother sinks the moment.
Happens to Ranma and Akane in Ranma ½ from as early as the Ice Skating battle. In response to that storyline (it makes sense when you see it,) Ramna was dared by Akane to kiss her. As he worked up the raw nerve, he leaned in closer to her, and paused for just a brief moment, hesitating. He tells her that they should save the kiss for someone they love. She says then he can't do it with her, and he angrily replies he has not told that. The two of them get a Luminescent Blush, it looks like if they are going to kiss... and then Ranma notices the other family members watching from a door, encouraging him to "Just kiss her!"
A much more infuriating one comes from late in the manga. After the parents have told him that the only way to get Akane to give up the Battle Dogi is to, basically, seduce her, Ranma pulls her into a closet for a "sincere" chat. He realizes very early on that, while she's being honest and affectionate, his intentions were not, which makes him feel like a miserable scumbag. Having realized this, he abandons the "plan" and then proceeds to talk to her with his true feelings, and the two of them embrace and come the closest ever to a real romantic kiss... only to have the entire family barge in, and Soun reveals that Ranma's goal was to make her give up the Dogi. Understandably, Akane's anger exploded like never before or after in the manga.
A favourite trope of CLAMP's, it shows up particularly in Cardcaptor Sakura. Every time Touya starts to tell Yukito about his other self (in their Yaoi Guys pose), someone interrupts. Of course, the interruption is usually deliberate. For what Touya is to Sakura, Meilin is to Syaoran.
It happens between Syaoran and Sakura in the manga as well. Late in its run, he tries to work up the nerve to tell Sakura what he truly feels for her, but he always gets interrupted by things ranging from Kero-chan wanting to take a picture of her to people yelling loudly over at Seijou High because Yukito fainted in the middle of the athletics track.
And then every other scene in the second movie.
Every time Keiichi is about to get his nerve up with Belldandy in Ah! My Goddess!, something happens. It often involves explosions or magic SNAFUs.
In an early chapter, in order to keep her title as Campus Queen secure, Sayoko Mishima tricks Belldandy into leaving the scene and she pretends to come on to Keiichi. Just before anything happens, a bunch of water falls on her from a window above, thrown out of a bucket by someone who didn't see her there. Keiichi is relieved.
Miroku and Sango have a mutual genius for this, no third party interference required. Miroku is the most frequent offender thanks to his habit of copping a feel just when things are going well, but Sango has been guilty a few times as well:
It happens so many times that at one point the series double-subverts it: finding Sango downcast after an encounter with her little brother, Miroku sits beside her to comfort her, and, atypically, remains perfectly chivalrous until Sango remarks that she would have expected him to try groping her by now. Miroku being Miroku, he promptly offers to make up for his omission if she wants him to. Guess what.
There's the other time that happens, of course, where she gropes him (expecting to find Shippo's tail, because of course Miroku would never have so much tact to properly comfort her).
Inuyasha and Kagome aren't quite as bad, but they catch their share of examples:
The most agonizing occurs late in the manga and is reproduced in The Final Act, during one of Kagome's visits to the present, when her family manages to return from a spontaneous hot spring vacation at precisely the wrong moment:
Kagome: [Hugging unconscious Inuyasha] You've been fighting so hard, even though you're a human now… [magically shrunken Miroku and Shippo pop out of Inuyasha's hair] Miroku: Ah-heh… we're not interrupting anything, are we? Kagome: AIEEEEEEEEE!
Every time Keitaro and Naru in Love Hina come close to kissing or admitting their feelings for one another, someone will inevitably barge in on them or Keitaro will suffer an Accidental Pervert moment and provoke Naru into Megaton Punching him. Even after they finally kiss and become an officialOfficial Couple in the manga, Moment Killers still abound whenever they try to consummate their relationship.
This occurs in a romantic moment in Elfen Lied between Kouta and Yuka, in which Nyu promptly jumps out, startling them both and ruining said moment. Luckily though, she's completely naked.
Kaoru and Aoi get this a lot in Ai Yori Aoshi. Most of the cast Moment Kills by accident, but Miyabi, being the Mama Bear she is, does it on purpose. She mellows eventually.
This trope might have been taken a bit too far in Code Geass's second season, where the Tsunderes, Lelouch and Kallen, rarely have a single conversation that did not go down this path (with each Moment Killer becoming more ridiculous than the one before it). It could be assumed that this really bothered the fans of this pairing. To make it even more torturous for them, the only uninterrupted conversation they have during the whole season ends with Kallen kissing Lelouch, but since he's moments away from turning himself into the enemy of the entire world and doesn't want to drag her into it, he doesn't respond to any of it, leaving Kallen with the impression that he feels nothing for her, resulting in Kallen bidding him farewell and walking away, with him sadly whispering goodbye once she's out of earshot.
Ironically, in R2 episode 24, Lelouch and C.C. have a very touching moment together, and it's interrupted by Kallen bursting through the wall to kill Lelouch. A few fans joked that this was revenge for C.C. interrupting a near-Accidental Kiss between Lelouch and Kallen earlier in the series in a very "mother walking in on her son and his girlfriend making out" fashion.
Almost everytime Saito and Louise come together in Zero no Tsukaima. It gets worse and worse. Especially once you consider that it keeps happening during the third season as well, despite the fact that they got engaged at the end of season two. One would assume that once they actually got married at Season 4's end, they can finally do something. Saito's mansion should be big enough for that.
Sousuke himself tends to do this to Kaname. Especially when she misconstrues his actions as being "bold" and "romantic," only for him to completely obliterate any such hope by doing something ridiculous.
Kaname does it to herself in episode 9 of The Second Raid during the haircut scene. Finding that Sousuke has fallen asleep while she was trimming his hair, Kaname comes very close to kissing him, but stops short when she realizes what she's doing and decides it's time to dunk his head in the sink instead.
Inverted Trope in Digimon Frontier. In episode 46, Takuya and Zoe are talking in the library when Takuya blurts out, "I really like you." Cue Luminescent Blush by Zoe and then by Takuya when he realizes what he just said. By the time Izumi tries to respond, Takuya is sleeping. In this case, the Moment Killer was one of the people that would benefit from the completion of the moment. ...The shippers were not amused.
Germany: Hey! Don't run off when I'm having a moment!
Anytime Nike and Kukuri have a tender moment in Mahoujin Guru Guru, Gipple will inevitably pop up screaming for a barf bag.
Naruto and Sakura were having a moment and Sakura was about to feed Naruto ramen when Sai pops in as the Moment Killer — and offers to feed Naruto himself, which Naruto was not pleased about. Kakashi ends up being the one who feeds Naruto, which doesn't please anybody.
Soul Eater: Happens with Soul and Maka, when Maka is standing beside Soul in the infirmary after the fight with Crona, in which he was seriously injured. Maka is tearing up and in the middle of some kind of Heroic Vow when Black☆Starcrashes into the room and starts yelling at the top of his voice as he practically strangles an unconscious Soul on the bed in an attempt to wake him up. Most shippers felt that the Maka Chop that came after was well deserved.
After Tsubaki narrowly defeats her corrupted brother Masamune and is in tears, Black☆Star comforts her with a hug... and then one of the angry villagers smashes a stick over his head.
In the final episode of Tenchi in Tokyo, just when Ryoko was about to kiss Tenchi, Washu pops out of the tree trunk where Tenchi and Ryoko are standing, to test her new and improved Dimensional Tunnel. She was then followed by Sasami, and then Ayeka, and finally Mihoshi and Kiyone.
Dee and Roy in FAKE are all but guaranteed to have the moment killed for them. The most frequent offenders are Bikky and JJ, who do it on purpose, but there's also that time when Ryo fell asleep right after kissing Dee and that other time when Dee's phone rang just as things were getting hot and heavy between the two of them. No wonder it took them seven volumes — which is quite long indeed for a Boys Love manga — to officially get together.
Bleach: Good job, Nel, you kind of ruined the quiet, subtle, heart filled moment between Ichigo and Orihime, which essentially counted as their true reunion. Not that you diving into Ichigo's, uh, lower abdomen area wasn't cute in its own way, it's just, you killed that sweet moment.
In chapter 228, Rukia and Orihime are veering dangerously close to a Les Yay moment, and Hiyori quite literally falls from the sky and drags Orihime off. Moment killer much?
This trope is essentially the only reason it took Please Teacher!'s Kei and Mizuho so long to, oddly, do anything at all... except hook up. Huh. His annoying and oft-tragic condition doesn't help matters much.
Konoka has her own share of moment killing. On the same pair nonetheless.
Nogizaka Haruka no Himitsu uses this trope extensively, with the primary offenders usually being the sister and maids who are supposedly rooting for them to get together.
Wataru of Hayate the Combat Butler blocked himself. Nagi'd stuffed Isumi in a coffin so she could listen in while Nagi talked to Wataru about the problem of the week. She manages to get him to confess to liking Isumi, then turns to Isumi and asks if she needs anything more. Wataru fiercely backpedals and claims it was a joke. The audience weeps for his crush.
In Little House with an Orange Roof, Natsumi and Shou are interrupted by Natsumi's sister. Unusually, the killer immediately realizes what she was interrupting and attempts to remove herself from sight.
In Baka to Test to Shoukanjuu, when the whole building was falling down and everyone forgot that there was an ESB going on, Akihisa and Yuuji were saving their respective partners. Everyone was going awww and suddenly, Yuuko Kinoshita just HAD to defeat Yuuji's summon. Class A won because of it.
In Kannazuki no Miko, Himeko and Souma have their first kiss, when Himeko starts crying.
In Gankutsuou Albert and Eugenie are about to kiss in one scene but are interrupted by Andrea.
In Omamori Himari, its practically a Running Gag for one of the girls starting to get intimate with Yuuko...only to be violently (and, oftentimes, hilariously) interrupted by one or more of the other girls.
This trope is the only thing stopping this from being a hentai... not that it's that far away to start with.
In Special A Yahiro and Megumi are about to kiss when Tadashi rushes by on a motorcycle, yelling "Hey, Yahiro! I'm borrowing your bike for a moment!" Yahiro responds "Can't you read the atmosphere here?"
Pokémon - In the anime, Brock's Croagunk! Any time Brock gets excited around a woman, he leaps into action with a Poison Jab attack, right in Brock's ass. Brock will collapse and be dragged off. Before Croagunk, variations where Misty or Max would drag him off by the ear or Bonsly tackling him with Double-Edge used to occur.
Team Rocket also plays this sometimes, like during the final episode of Diamond and Pearl. As Piplup and Pikachu are sobbing into Togekiss's chest because Ash, Brock, and Pikachu are going back to Kanto, Team Rocket comes in with another stupid capture attempt. This is then turned into a Crowning Moment Of Awesome as not only does Ash deliver a Shut Up, Hannibal! moment via a Brave Bird, but Team Rocket gets freaking Curb Stomped.
Not quite as harsh as it was cute, but Ash's Chikorita(before she evolved) would snuggle her trainer when being called out which could throw off the pace of, say, a Gym battle.
Ageha and Tsutomu of Toshiue no Hito are university students living together after a rather fraught courtship. It could be the temporary flatmate or one or all of the members of his literature club or even his parents coming to see why he's living with an older woman, but it seems that no matter what, someone will interrupt their chance of being intimate, often as they're in the middle of taking their clothes off. It's that kind of series.
In episode 4 of the first Koihime†Musou OVA, Kan'u agrees to sleep with Sousou in exchange of sparing the life of Bachou, who had tried to murder Sousou earlier in that episode. That night, the two are quite blatantly about to have sex... And then Sousou suffers ANOTHER attempt to her life, this time by an unknown assailant who sneaks in her tent from the ceiling. Moment Killing at its best there.
Episode 10. When Mariel is washing Taro's back after a long day he turns to her and their faces move together for an Almost Kiss...then Ikuyo Suzuki runs in yelling to break it up.
Episode 15. When Taro and Mariel are having an intimate moment, an unnamed (as yet) Yashima Sanae breaks into their room in search of Taro (who was identified as an intruder earlier while in disguise).
Keroro Gunsou: As if Momoka didn't have enough problems trying to confess her feelings to Fuyuki, frequently her attempts to have a private moment are derailed by somebody else showing up at the most inopportune time. Notably, this isn't always the fault of one of the keronians; often it's Natsumi or Koyuki who unknowingly butts in.
There's even an entire episode devoted to finding a situation where no one would interfere, and eventually had to find a way to subvert the accidental moment killing nature of nearly the entire cast.
In Chapter 81 of Ouran High School Host Club, Haruhi confesses her love to Tamaki. The moment was totally ruined when Tamaki made an absolute fool of himself by yelling to Hikaru what she just said, falling to the floor, being called a narcissist when he accepted her confession, and being called an idiot. Haruhi then shouts that she's not sure if she still loved him. After all that, he ends up kissing her, which made Hikaru cry.
The most famous one is probably in Both Of You Dance Like You Want To Win! when Asuka falls asleep right next to a wide-awake Shinji, who tries to lean forward to kiss her... until Asuka calls for her mama note (at which point Shinji abandons his futon and goes to sleep on the other side of the room).
Then a couple of episodes later, Asuka decides she wants to try kissing Shinji using the "I'm bored" (and the "well if you're too scared to..." tactic to goad Shinji into agreeing), and then ruins the mood herself by holding his nose (the tragic part is she pinched his nose to pretend it was not a big deal in case of he rejected her. But precisely because she was trying playing it like not a big deal, Shinji did nothing, and she thought he was rejecting her).
Kaji and Misato also get their fair share (usually with Misato killing the moment before things go too far... at first).
Kenichi: The Mightiest Disciple: After over 400 chapters of seemingly being oblivious to the true feelings of Kenichi, Miu finally admits that she feels similarly... only to have her overprotective grandfather suddenly burst in, spewing intense amounts of Killing Intent, scaring the hell out of Kenichi and Miu in the process, the other Ryouzanpaku masters struggling (and failing miserably) to hold him back.
In Fruits Basket, there's a scene wherein Yuki starts telling Tohru how cute she is and they move closer and closer...until Ayame comes in talking about how romantic the scene was. Yuki, naturally, decked him.
Beatrice pulls this on George and Shannon in Umineko No Naku Koroni. After Shannon asks George to tell him that he loved her, Beatrice just trolls up, and replies:You really thought I'd let him say it? DUMB ASS! and then kills them both.
This makes up much of the humor of the yaoi manga I Can't Stop Loving You as Kyouji and Yu's attempts to have sex are constantly thwarted by causes ranging from ghosts to people walking in on them to Yu accidentally crushing Kyouji's ribs with his Super Strength...
This happens in Rosario + Vampire to Tsukune and Moka, courtesy of... pretty much everyone else.
In A Certain Magical Index, Touma and Mikoto dance together, then Koroko dropkicks Touma in the back of the head. Kuroko has a tendency to ruin tender Mikoto moments here and in the sister show A Certain Scientific Railgun due to her jealousy and perversions.
Touma once cock-blocked his own father by barging into the room when his parents were about to have sex and asking if he could sleep in their bed. He had a good reason: his mother was in Index's body, though his parents were unaware of this.
The stated purpose of The MK5 from Beelzebub. Seriously, that's what they like to do. If there's any kind of moment, be it action or romantic, the MK5 will show up and do what they do best.
In Black Bird a fair bit of what keeps Kyo and Misao from having hot demon sex is unexpected and ill-timed interruptions by his servants while the couple are making out and really, really horny.
Rurouni Kenshin: Right before Kenshin goes off to fight Shishio, Kaoru has a heart-to-heart with him and wishes him well. Then Yahiko interrupts from where he was eavesdropping, yelling that she should have been more forward with his feelings.
In the Daily Lives of High School Boys skit High School Boys and the Literature Girl, Hidenori was entangled in an unwanted love tension with a girl he knew nothing about, and he called in his friend Tadakuni to break this up. Tadakuni did this beautifully, despite being punched out by the girl afterwards:
Tadakuni: Hey, this is bad! The potato chips at that convenience store are half-off! Let's get going!
Strangely, Hidenori, Genre Savvy as he is, did not initially recognize it was this trope that Tadakuni was invoking, and only got it after a few seconds.
In Gintama, Otose and Unlucky Childhood FriendJirochou are recovering in the hospital after the harrowing attack on Kabukichou. After all the killing and mayhem (including Jirochou putting Otose in the hospital in the first place), the two old friends finally get to say what they need to say to each other after so many years and so much heartache. Then the hospital room doors bust open and pretty much the ENTIRE SUPPORTING CAST falls into the room from where they had been eavesdropping. The guy in the third hospital bed in the room chews them all out for interrupting "just when it was getting to the good part."
On Shirokuma Cafe, Handa the zookeeper has a crush on Sasako, the cafe's waitress. One night, after the cafe holds a ghost story night, she offers to ride her bike along side him on the way home as he's afraid of ghost stories. He almost accepts when Llama cuts in and offers to take her place as he's going the same direction as Handa.
Annasui: I can't wait to tell her... It's now or never! My feelings for her are genuine! I even paid a shitload of money to get this ring from the prison merchant. [Slips it on her finger] Once she wakes up... I want her to... I want her to know and embrace my feelings for her-
Hermes: Hey! Look! It's an alligator! There are fuckin' alligators around here!
Invoked in Hellsing: Seras manages to defuse a potential battle between Alucard and Andersen using a old tourist comitive. They both comment about the lack of atmosphere and back off.
Chocolat Misu always manages to do this whenever her sister Tira is having a cute moment with Carrot. Justified in that she's in love with Carrot and actually has no idea Tira feels the same way.
The Idolmaster 2 The World Is All One has Hibiki and Yukiho act as Moment Killers on a regular basis, usually through the accidental reveal that they've been eavesdropping in the Producer and Haruka's heart to heart moments.
Inverted in Death Note, where Light wants to concentrate on the plot but his girlfriend Misa continuously has other ideas - not that it ever goes anywhere, Light being Ambiguously Gay at best. A general fandom favorite:
Light: (monologuing) At any rate, it's probably best not to be seen with Misa for now.
When Wonder Girl (again) and Supergirl reunited in Teen Titans there was the extremely close hug, actual "I love you", leaning in... and being shot with a rocket launcher by Ravager, who apparently enjoys having invulnerable teammates.
A preemptive one can be seen in Scott Pilgrim as Scott's plan to cuddle with his girlfriend is ruined by his gay roommate sitting around in his underwear.
Even Batman can fantasize about Poison Ivy in the shower... until Alfred turns the water cold.
Similary to the movie, in Superman: Secret Origin right when Superman and Lois are about to kiss, Jimmy interrupts. Lois is understandably annoyed, but Superman acts like it's nothing.
In the Mekanix miniseries by Chris Claremont, Kitty Pryde and Karma have just collapsed a building on top of a small Sentinel, with Kitty using her phasing powers to bring the two of them down to the ground safely. Kitty lands on top of Karma as the two laugh in relief, and they seem about to kiss. Then it turns out the Sentinel wasn't as defeated as they thought, and they almost die with the moment.
Just when Kanae was going to kiss her Sempai in the Haruhi Suzumiya fanfic Kyon Big Damn Hero the unnamed enemy slider appeared himself to get her. It doesn't help that the enemy slider dislikes both of them and he has been searching for Kanae for a long time (the last time he lost Kanae was one month ago).
The AmericaxEngland fanfic You Can't Take The Sky From Me has America and England talking about their pasts while in England's cabin, culminating in an Almost Kiss... before Prussia walks in.
In the Looney Tunes story, Defying the Odds, whenever Sylvester comes close to telling Tweety how he feels about her, he is interrupted. Luckily, he is finally able to tell her when they are at Paris.
In Twisted Fates, Yomiel has just got home from work and really wants some quality time with his wife. Sissel, however, really needs to talk to him and breaks up the moment rather unceremoniously. He feels bad about it, though.
In the DC Nation plot "Heaven or Las Vegas," Jade and Kyle are laughing themselves silly over the completely crazy scenario they're trapped in, and making out after a brief tussle with a Yellow Lantern construct. Then, the Star Sapphire flies in.
Jade: OH HELL NO YOU DON'T! I'm - We're - having a moment here!"
In Dave Stdider Pokemon Traner, Terezi and Dave are lying naked in bed after kissing, just as they are about to have sex, Will Turner bursts in the door and tells them that they can't have sex without "Condominuims". Then Dave realizes that he's got more important things to do than banging Terezi, such as exorcizing Giratina from his friend John and leaves her alone naked. The moment is further ruined when Karkat comes in and takes a naked picture of her. Then Jack uses it to blackmail her and stabs Will. Basically, this is the WORST ruined moment in history.
Almost every fanfic for The Cat Returns has this with Haru and Baron, usually in the form of Muta, Hiromi, Toto, Lune, Yuki or a combination of the five. This is especially true in the ones where they have the barrier of Baron being a Creation and Haru a human.
In a non-romantic example, Pretender has Sumia accidentally interrupt Chrom when he attempts to have Robin open up after his suicide attempt. Robin quickly uses Sumia as an excuse to get out.
In The Little Mermaid; Ursula does this intentionally to prevent a kiss between Eric and Ariel. It has a bit more behind it, though — she's not specifically trying to keep them apart, but instead trying to keep Ariel from fulfilling the terms of her Deal with the Devil.
Happens several times between Bernard and Bianca (involving a marriage proposal rather than a kiss) in The Rescuers Down Under.
In Aladdin; Jasmine and Aladdin were having a moment at his sleeping spot and talking about how they both feel trapped by their circumstances. About to kiss, they are interrupted by the palace guards arriving to rescue Jasmine and arrest Aladdin.
In Hercules; Megara and Hercules were having a post-date conversation and falling in love when Phil arrives with Pegasus to interrupt and chastise Hercules for sneaking out on him. Making the best of the situation, he gives her a flower and a kiss on the cheek before he leaves and that leads to Megara's "falling in love" song.
Donkey does this constantly in the Shrek films. Often to say stuff like "Isn't this romantic?"
Used as a Running Gag in Chicken Run. Every time Ginger and Rocky try to kiss, something interrupts them. (Mostly done because the animators had no clue how to make two chickens kiss...)
WALL•E - Another subversion of this trope pops up in the final scene: WALL-E and EVE finally hold hands, staring lovingly into each other's eyes while WALL-E's tape of Hello, Dolly!! reaches the "It Only Takes a Moment" scene. Just then, the broken robots and M-O arrive to greet the two. Fortunately, M-O recognizes that WALL-E and EVE need to be left alone, and he shoos the other 'bots away.
Cars: McQueen and Sally are interrupted by Mater on the Dinoco helicopter.
Judge Dredd. The title character and Judge Hershey are having an intimate talk in Hershey's trashed apartment. Herman Ferguson, the comedy relief sidekick who's been tagging along with Dredd, walks in and interrupts them, then says "Is this a bad time?"
Back to the Future: Marty and Jennifer are dreaming about things in the clock-tower square and are playfully flirting, coming close to a kiss. But it is interrupted by an activist asking for donations to save the clock tower, setting up the Chekhov's Gun about lightning hitting the tower later in the film. At the end of the movie (or the beginning of Part 2), the return of the Delorean from Doc's trip to the future interrupts another kiss.
In The Dark Knight, Rachel and Bruce are on the balcony outside the large fundraiser for Harvey Dent. Just as they look like they're going to reconcile romantically, Dent comes in abruptly. To make matters worse, the Joker breaks in with his gang and promptly begins shooting up the place looking for Dent.
When Harvey was proposing to Rachel, Bruce appears out of nowhere to knock him out and drag him to a closet because that's when the Joker appeared, looking specifically for him.
Of course, Rachel misunderstands this at first and thinks that Bruce is attacking him out of jealousy.
Another balcony scene: in Iron Man, Tony and Pepper are talking outside one of Tony's annual parties. They almost kiss, and stop when both of them realize how awkward the situation is. Pepper asks for a drink and Tony goes downstairs. A related scene at the end of the movie, Tony and Pepper share a tender moment when he reminds her of "that night" on the balcony. Pepper then reminds him that he forgot to bring the drink back upstairs and left her waiting.
Happens AGAIN in the second movie. After Tony and Pepper finally kiss for the first time, Rhodey interrupts them and calls them "two seals fighting over a grape."
In another Mel Brooks film, Robin Hood: Men in Tights, after defeating the Sheriff of Rottingham and finding his key fits Mariam's Chastity Belt, Robin was about to unhook her when Mariam's nursemaid storms in, declaring: "Before you do it, you must go through it!... or else I blew it." Cue Robin snapping his fingers in frustration at being cock-blocked.
Zenon: Zenon and Greg mutually are guilty of a fatal fumble on this one. At one point they are sitting side-by-side, facing the same direction, with awkward silence. Zenon tells Greg that if he wants to kiss her he should just do it already. After a pause, they both turn towards each other at the same time - and accidentally smash their faces into each other.
Mikaela in the Transformers film improvised and used this as an excuse why Sam was acting nervous and jittery when his parents came into his room: "He was hiding a girl." And his parents fell for it enthusiastically, actually really happy about it. Of course the real reason was that anxious alien robots were in the backyard.
The entire Harry Potter and the Half-Blood Prince film is just one cockblock after another for Harry. After Dumbledore ruins Harry's chance with a cute waitress and Hermione smacks him for even looking at Romilda Vane, he then has this happen twice with his true love Ginny. The first time, Ron sits down in the couch between them with an oversized plate of pies. And it just gets better when a bathrobe-clad Ginny is interrupted in kissing Harry when a gaggle of Death Eaters come right the frig out of nowhere and wreak havoc upon The Burrow. Later he finally gets one tiny kiss...and she's gone when he opens his eyes. Oh well, maybe next time. After Voldemort's defeated, or something.
Imagine Me And You: the long-awaited make-out scene between Luce and Rachel is interrupted by the sound of Rachel's husband's voice.
The X-Files: Fight the Future: When Mulder and Scully are about to kiss, Scully is stung by a bee. Unless, of course, you watch the blooper in which Gillian throws David against the wall, kissing him, or a real deal deleted scene, in which the two actually do kiss, prompting Mulder to pick Scully up and go...offscreen.
In Notting Hill just before the "I'm also just a girl, standing in front of a boy" speech, Will and Anna are interrupted by a random customer and by a phone call from Will's mother.
From Enchanted, during the ball scene, Robert and Giselle were dancing together, including Robert singing softly in Giselle's ear (when he earlier claimed that he didn't sing), leaning quite close to each other, when Nancy and Edward interrupted them.
Charlie: (after making out with Jessie under a waterfall) Okay, I'll admit it. This is the most romantic moment of my entire life. (Louis screams and cannonballs into the water near them) And now it's over.
In the first Christopher Reeve Superman movie, Supes goes back in time to save Lois from death, the two are just about to smooch — and then Jimmy Olsen runs onto the scene and wrecks everything.
Total Recall (1990) (1990). As Quaid and Melina are kissing in the Martian catacombs, the rebels show up and take them into custody.
In Crouching Tiger, Hidden Dragon, Shu Lien was apologizing to Mu Bai for letting the sword get stolen, believing that was the reason why he had came to see her. He said that he did not hear about the stolen sword until he arrived in town, implying he came specifically to confess his feelings towards her. When he was about to say it, a servant came in, interrupting them.
Jason starts to do this to himself in Mystery Team as he shares an extended embrace with Kelly, by commenting that her skin feels like what he imagines a dolphin's does. Before this sinks in, Duncan vomits dog urine on the two of them.
This makes up Trick's entire plot with Mark and Gabriel's attempts to have sex being constantly thwarted by demanding friends. Interestingly, this is actually implied in the end to be a good thing as Mark and Gabriel were originally planning on a one-night stand only but ended up forming a genuine emotional connection somewhere amidst their continual interrupted meetings.
Jack Sparrow in Curse Of The Black Pearl. Will and Elizabeth are finally about to have their first kiss, when Jack makes a huge noise in the next enclave, completely oblivious.
Time Bandits. Vincent and Pansy are about to kiss when a time door opens above them and the dwarves (and Kevin) fall on them.
10 Things I Hate About You combines this with Above the Influence. Kat got fairly drunk at a Wild Teen Party and Patrick spent most of the night taking care of her and she had sobered up somewhat by the time they got back to her home. She puckers up, ready for a kiss and Patrick pulls away, which was actually the first evidence that he was starting to fall for this girl rather than being in it for the money. Of course Kat didn't understand that at the time and left the car in a huff. A Hilarious Outtakes moment goes much differently, where Heath Ledger (Patrick) instead pulled Julia Stiles into a big, sloppy kiss.
You Only Live Twice. James Bond and Kissy Suzuki are exploring an island for the enemy base they know is there. Just as they're about to take some private time with each other, a SPECTRE helicopter flies overhead and into a volcano's crater. This tells them where the base is, so they have to break off their fun and get back to work.
A much earlier example of the meddling robot (a la C-3PO / Dot Matrix) appears in the Robert Sheckley short story Human Man's Burden. Every time the man and the woman start edging towards expressing their true feelings, an obnoxious marrying-bot bursts in, ruining the moment. Some other robots finally physically restrain the intruder long enough to allow the couple to clinch.
Thursday Next's time-traveling father does this to Thursday and Landen in the first book when he shows up (freezing time for everyone but himself and Thursday) to have a chat with his daughter about the invention of the banana — while she and Landen are having a moment.
That's exactly what happens in Harry Potter and the Deathly Hallows, when Ginny invites Harry to her bedroom to give him his birthday present (a kiss). How far they would've gone is debatable, but they clearly would've gone past "thank you for the gift" if Ron hadn't shown up to assassinate the moment. In the film Ron is replaced by George, who knows exactly what he's doing.
Later, Harry takes a turn as moment killer for Ron and Hermione - though he does have a good reason.
Harry: OI! There's a war going on here!
In the third Kate Daniels novel, Kate and Curran are having hot and heavy makeouts in a hot tub when oblivious Derek comes in and asks Curran's opinion on another matter. After he leaves, Kate shuts Curran down cold, the break giving her a chance to regain her willpower and her resolution not to get romantically involved.
In Time Enough for Love, when Lazarus and Maureen are headed off for an adulterous note and incestuous by virtue of Time Travel, but that's not relevant to the example tryst, their moment is well and truly murdered by the abrupt appearance of Maureen's five year old son Woodrow, who stowed away in the car in the hopes of getting a trip to the amusement park. Their reluctance to continue is prompted not so much by concern for Woody's innocence as much as his complete inability to keep his mouth shut.
Happens multiple times in Audrey, Wait!. Random Accident varieties are from the customers in the Scooper Dooper, and Sharon is the jealous rival type.
Happens twice to Katniss and Peeta in the first two books of The Hunger Games. Both times they are kissing and she begins to feel desire for him. The first time they're interrupted by her bleeding head wound; the second time by lightning hitting a tree.
Named from a running gag in an episode of Scrubs. Whenever J.D. worked up the nerve to ask Kim out on a date, Elliot would step in and chat with her girl-pal. Cue title-card: Elliot Reid: Moment Killer. The series itself is filled with many other examples.
Elliot/J.D. had this happen to them in one of the earliest episodes, when J.D. is growing closer to Elliot and were about to kiss for the first time, only to be interrupted by Dr. Cox. J.D. noted that in such a situation he had 48 hours to actually kiss her before he entered "The Friend Zone" and spent the next two days trying to get that kiss. Right at the buzzer they were about to kiss again, only for Elliot to confess their work life was too hectic to consider a relationship at that point. Note that J.D. and Elliot are the Official Couple of the series, so that was just the start of their Unresolved Sexual Tension.
According to Elliot, he does this a lot. Immediately after she warns him not to do this with Julie, ruins the moment by telling her she smells like his mom, which he saw as a compliment. The next day, he tells her what he actually said she smells like "mummum, a rare flower", and it worked.
Game of Thrones: The foreplay between King Renly Baratheon and Ser Loras Tyrell is unexpectedly interrupted after Renly starts kissing the bruises on Loras' chest. This reminds Loras of the humiliating defeat he suffered at the melee competition earlier in the day, and it kills the mood.
Two episodes, both involving Greg and on-and-off girlfriend Rachel at a drive-in movie. Neither progress to sex, but it's clear both are hot to kiss – big time (especially by 1970s standards):
"The Big Bet," Greg and Rachel clearly wanted to kiss. Problem: Greg – as part of losing an earlier bet to his younger brother, Bobby – has been forced to bring him along. Bobby, in this Annoying Younger Sibling tale, is a cross between Random Accident (tearing the top of his dad's convertible) and Deliberate Destruction (when Greg and Rachel begin to snuggle up, Bobby – who is sitting in the back seat – complains that he can't see).
In "Greg Gets Grounded," aired a year later, Greg has gotten to ask Rachel out again, and again go to a drive-in movie. Clearly, a huge lip-lock is on both their minds ... when suddenly a frog jumps from the back seat onto Rachel's head. Greg, it seemed, had forgotten to remove his brothers' box full of frogs from the back seat; he had taken Peter and Bobby to a frog-jumping contest as part of an earlier agreement. This incident is a Random Accident.
The off-screen romance between Barry Williams and Maureen McCormick hit its peak in 1973. Williams details a "Deliberate Destruction" encounter in his book "Growing Up Brady," where he and McCormick had gone up to Williams' room (after supper at Williams' parents' house) to listen to records ... as foreplay to you-know-what. The two had all but undressed when – on Williams' stereo – the Pink Floyd album The Dark Side of the Moon dropped onto the turntable. Williams recalled that his father heard the start of the first song and immediately knew what was about to happen. A stern rap on the door ... to announce that dessert was ready, of all things ... followed.
Step by Step: A season 2 episode saw Dana and a boy named Mike go to a Make-Out Point-type location to ... well, make out. Cody learns about the date and informs Frank that Mike is bad news, and the two make a buffoonish attempt to make sure Mike is not doing anything bad to Dana. Frank climbs onto a tree and tries to get a closer look when he falls into the back seat of Mike's car. Dana, needless to say, is very angry at this "Random Accident"/"Deliberate Destruction" attempt ... but not as angry as she would have been had Frank accepted Cody's stupid suggestion to don a beaver suit. (Cody's perception of Mike turns out to be well-founded, as later in the episode, he tries to get Dana to let him go up to her room to have sex and gets aggressive. Frank walks in and runs Mike off.)
Happy Days: Two instances, both in the opening credits, are well known to fans:
Seasons 1-2: A teen-aged couple is making out at Inspiration Point ... only for the car door to accidentally open and the two to fall out. Richie and Potsie, who are in the car parked next to them, witness the incident; Potsie is amused and laughing his ass off, but Richie doesn't see what's so funny.
Which makes one wonder what Potsie & Richie are doing at Inspiration Point with each other.
Season 10: One of the clips shows Fonzie moving in for a kiss with girlfriend Ashley Pfister (Linda Purl) ... only for Ashley's daughter, Heather (Heather O'Rourke) to pop in unexpectedly. Both Fonzie and Ashley just laugh, as Heather is sooooooooooo adorable! (Perhaps the intent of the producers was to pass off the character of Heather O'Rourke as adorable.)
Full House: Through a combination of unconscious design and Idiot Matchmaker, 5-year-old Michelle — desperate to have a mother — tries to match her father with her kindergarten teacher. To set the mood, she makes them both peanut butter sandwiches ... then, a few minutes later (through 5-year-old patience), innocently asks "Are you in lllllooooooooovvvvvvvvvvveeeeee yet?" (Of course, the 35-year-old Danny realizes what's going on and explains to his disappointed daughter that her teacher — who is in her late 50s — is married and that romance isn't going to happen.)
In another episode, Jesse and Becky are trying to have sex, but Michelle keeps innocently knocking on their door every few minutes asking them to play with her, even in the middle of the night.
Spencer does this to all 3 of them: he cockblocks Carly hard in her attempt to kiss Shane in iSaw Him First; when Freddie hits on Carly in iDon't Wanna Fight, a flush is heard from Spencer's toilet; and as for Seddie fans, Spencer breaking in to find his banjo before they even answer Carly's question if Sam and Freddie liked their kiss.
The episode iSaw Him First is quite full of moment killers where both girls attempt to kiss Shane first in all futility.
In iSaved Your Life Mrs. Benson abruptly interrupts as Carly and Freddie are in the middle of a heated make out session. In his bed. With Freddie having just come out of the shower, wearing only a bathrobe.
In Zoey 101, one of iCarly's spiritual predecessors, this becomes a Running Gag. Every time Chase tries to tell Zoey he's in love with her, someone always interrupts. Fittingly, he ends up telling her completely by accident.
Constantly occurring in the seventh season finale. Nearly every supporting character from the episode enters at one point or another, interrupting Niles confessing his feelings for Daphne.
Also in the seventh season, Frasier and Roz come quite close to hooking up when Kenny barges in unknowingly interrupting them. Of course Frasier and Roz do eventually sleep together in season 9, the aftermath of which can be seen as closure for Frasier/Roz shippers who can now see that they are better suited as Just Friends.
Parodied in the SM:TV Live Chums sketches, "Me and Cat alone in the flat..." However, Mary being Mary, she understood they had to leave.
In season one of Soap, Burt and Mary attempt to have sex after he's cured his guilt-driven impotence with both of them being awkward and nervous as it's been a long time. As they start making out on the bed, a burgular tries to rob their house and then they receive a phone call that Jodie has tried to kill himself.
In the Firefly episode "Objects in Space", Simon and Kaylee are talking, one thing leads to another, they both lean in, about to kiss for the first time, and then Book interrupts by accident.
Simon also has the dubious distinction of having killed at least one moment on his own, though. When alone with Kaylee, in a freak show of sorts, he gives as reason that he is attracted to her, that she is the only woman in his life who is neither married, a "professional," or a close blood relative. He is, of course, trying to say that Kaylee is the only girl for him, but Kaylee completely misunderstands and Simon's unable to articulate himself well-enough to clear up the confusion. The ensuing mess is best summed up by Wash, "Oh my God! It's grotesque! Oh, and there's something in a jar."
Mal had another moment, compounded by Kaylee's reaction. Simon and Kaylee get drunk. Next morning, Mal finds them fast asleep in the bar, cuddled up together. He pauses to double-take then deliberately kicks them awake. Even Kaylee's a little startled by the situation she and Simon find themselves in - Simon naturally panicks and tries to reassure Mal that he would never do anything disrespectful to Kaylee such as randomly sleeping around with her. It's fairly obvious what he means but Kaylee misinterprets it as him not wanting to sleep with her and takes it so badly she abandons him at the bar.
In Farscape Aeryn and John are stranded, apparently going to die. So of course they kiss and start taking off their clothes. Then D'Argo shows up, doing his Big Damn Heroes impression - easily a Crowning Moment of Funny what with Aeryn's pissed-off voice ("Someone's docking?!") and D'Argo's obvious amusement. Also notable is that Aeryn manages to be the moment killer in most of their future romantic moments. Though attacking spaceships, imminent death and Scorpius-take-overs do manage to contribute to aborted romantic moments.
John manages to do this when he walks in on Chiana and D'argo in the... er, middle of things, shall we say. Chiana, being Chiana, doesn't really mind the intrusion, D'argo however does, and calls Crichton on "killing the moment" for them (warning him in non too vague terms to please not do it again).
John: [panicking and covering his eyes] Sorry! Bad time. Uh, good time. Wrong time!
And of course the final episode (before the movies) had John and Aeryn in a row boat with John proposing However an alien species we've never seen before turns up and reduces them to small cubes of flesh.
Aeryn: You and your timing.
In The Office fourth season finale, Jim is about to propose to Pam, which the show had been hinting at in recent episodes, when Andy asks Angela to marry him.
Earlier seasons often featured Jim and Pam having a moment, only for it to be interrupted by the people they were actually with at the time...
There's also the end of "Waiting in the Wings", when Angel is trying to tell Cordy about his feelings for her...and then Groo shows up.
This happens quite literally in Life On Mars. Sam Tyler is leaning over the table to kiss WPC Cartwright... when his future self has an induced heart attack.
Count how many times Gene Hunt interrupts a heart-to-heart talk between Sam and Annie throughout both seasons. He's paid back in Ashes to Ashes, though.
Ashes to Ashes - Every time Gene and Alex get near each other, Shaz pops in with some vital bit of info or other. Jim Keats manages to pull off one hell of an epic cock block. Mind you, that was accomplished with pictures of Sam Tyler so maybe he deserves the credit after all...
Doctor Who - In a hearts-to-hearts between the Doctor and the Master, The Doctor almost persuaded the Master to come and travel with him through the universe. The Master is going all teary-eyed and mellow, there's a declaration of affection on the Doctor's part — and then Wilfred shouts his way into the conversation. Arg.
Turnabout is fairplay, though, since the Doctor himself is often guilty of this; most recently in "The Lodger", when Craig, his landlord and Hapless Nice Guy, has invited his best friend Sophie around to finally admit to her that he's in love with her. He's just about to blurt it out when cue the Doctor, having decided to rewire the house's electricity.
Buffy and Angel when they first kiss — Angel vamps out unexpectedly. This is how Buffy finds out about Angel's true nature.
A more long-lasting moment killer is when Faith started to teeter towards The Dark Side and Angel managed to capture her before she killed Xander. While talking her down and actually getting her to listen, Wesley burst in with a Watchers Council squad to apprehend her. This effectively ruined any chance to stop her before she made a full Face-Heel Turn. Although this was the start of a unique friendship between her and Angel because of being Not So Different.
The beginning of Season Two. Willow and Xander are out for a nighttime stroll, and Xander playfully dabs Willow's nose with ice cream. He's just about to kiss it off when they are interrupted by a vampire, which Buffy promptly arrives back in town to kill. Willow later attempts to recreate the moment, but by that point, Xander is back to being all hung up over Buffy.
Faith spies Scott Hope with another girl, knowing that he had dumped Buffy. So she swings into action and pretends to be an ex who has\had received several STDs during their relationship in a bid to get back at Scott for Buffy.
In True Blood, Tara and Eggs' first near-makeout is interrupted by Maryanne's servant carrying towels. Maryanne is not happy about this.
Maryanne: They didn't need any God damn towels!
In Merlin, Merlin accidently interrupts a tender moment between Gwen and Arthur.
Merlin and Arthur constantly serve as their own moment killers. The two of them are always stumbling into tender moments, only for one of them to freak out and toss a sarcastic mood-breaker into the conversation at the last minute. However, Arthur doesn't quite succeed at it in The Tears of Uther Pendragon, while Merlin is helping Arthur on with his armor before the battle... the moment happens, and the moment-killing element is too little, too late.
Arthur: It's not like you to get nervous, is it, Merlin?
Merlin: I'm not nervous.
Merlin: Because I trust in your destiny.
Arthur: Have you been on a sider?!
Merlin: It is your fate to be the greatest King Camelot has ever known... and your victory today will be remembered, by every age; 'till the end of time. long silence
Arthur: There are times, Merlin, when you display a sort of... I don't know what it is. I want to say - it's not wisdom. But yes. That's what it is. long silence fraught with meaningful looks Oh, don't look so pleased, the rest of the time you're a complete idiot.
Dan for Blair and Chuck on Gossip Girl in the season two episode where she has decided to take the chance and tell Chuck that she loves him. Ironic since she originally turned to Dan for help on how to get Chuck into bed without telling him she loved him (he refused to put out unless she confessed love and she didn't want to let him win) and Dan gave her a little speech that convinced her that it was better to take the chance and risk her pride for a shot at happiness. Dan then does a 180 and realizes he hates Blair so he intercepts her on her way to see Chuck and basically tells her she's doomed if she confesses love to Chuck Bass. She tells him he's wrong, but when she's face to face with Chuck she loses nerve and they end up arguing instead.
Also Vanessa in season one, when Dan and Serena try to have sex for the first time. Dan does it to Chuck and Blair again in the season three finale. Chuck's on one knee, box in hand, says "Blair, will you-" and then Dan punches Chuck for sleeping with his sister hours before.
Finn for Puck and Quinn, twice, in the same episode of Glee. First when the two were about to kiss, and then when Puck tells her he wants to be with her and their baby and she tells him he's special.
A horrifically literal example pops up in the Dollhouse episode "Getting Closer." Topher and Bennett do outright kiss. Moments later, Saunders shoots Bennett in the head.
The Mighty Boosh has a couple, albeit somewhat variated: in the first season episode 'Tundra' Howard and Vince are tied up and about to be frozen to death by the evil black frost. Vince and Howard break into a crimp; then Howard suddenly blurts out that he loves Vince. Vince starts to laugh, but when Howard becomes angry and hurt, Vince admits he loves him back. Then, seconds later, Dixon Bainbridge enters the ice cave and spoils the moment. It's variated because a) They aren't looking into each others eyes and b) it's somewhat unclear if Howard means he loves Vince in a platonic or romantic way. It's fairly obvious though that Vince meant his declaration romantically. The second, more brutal moment killer comes about in the episode 'Jungle'. Vince becomes fed up with Howard's constant worship of his mentor, Tommy, and asks Howard if he was in love with Tommy. Howard laughs it off; then Vince moves closer to Howard, looks into his eyes and asks if he ever kissed him. The moment is spoiled when Howard storms off.
Toward the end of Chuck's second season, Chuck and Sarah finally make out and start to have sex, but when Chuck gets a condom from his wallet, he only finds an IOU from Morgan. This sufficiently kills the moment that their relationship stalls for another season.
On Dark Angel the moment killer was Logan's eternally helpful PT, Bling and killing moments was very nearly his entire raison d'etre.
A non-romantic example in Supernatural. As Michael and Lucifer are getting ready to throw down, it's a dead serious moment, full of dramatic tension, Lucifer's "last temptation" to Michael, and they are ready. Then Dean rolls down the road, his car blasting Rock of Ages by Def Leppard. Cue Lucy and Mike going "Wtf?"
And then, of course, two seconds later when things have gotten tense again— "HEY, ASSBUTT!"
Remington Steele: According to Steele, the entire universe was involved in a vast conspiracy to prevent him from getting chummy with Laura Holt.
Laura: Why are they shooting at us?
Steele: Because we were kissing. Somebody always shoots at us when we're kissing!
Happened at least once between Wes and Jen in Power Rangers Time Force. And even after everything was spout the two never kissed.
Happens a few times in early episodes of Get Smart - in the pilot, Smart realizes 99 is a girl (after quite awhile), they draw closer, closer, and his dog Fang lets out a bark. 99 says "He's right." and they go after the bad guys.
An non-romantic version in The Pacific: Sledge and Snafu have just shared a sweet moment in which Snafu wordlessly comforts his friend over the death of his dog by leaning against his shoulder...and then Hamm barges in to announce that his brother was on a ship that was attacked by kamikazes. (Snafu: "Wow.")
Alias - Several moments between Sydney and Vaughn were killed: at the end of The Counteragent, Asst. Director Kendall interrupts a particularly tender moment between the two; at the beginning of Phase One, Weiss bursts into the "flirting corner" with exceptionally awful timing, though they later fixthat.
In the Fringe episode "Jacksonville," Olivia pulls one on herself, and yet another happens when she discovers Peter's glimmer before their not-date.
In the Better Off Ted episode "The Great Repression," Veridian's productivity plummets when Love Is in the Air due to the company's new lenient sexual harassment policy. Ted and Veronica are just about to succumb and start making out too when Ted's daughter walks in and kills the moment. Ted and Veronica realize they can harness the moment-killing power of children, and they have the day-care class marched through the office periodically to make the employees stop thinking about sex and get back to work.
Happens plenty of times in The Big Bang Theory, usually between Penny and Leonard. The biggest one would be mid-season two, in the Just Friends period between their first date and their official hook up. Leonard's mom, a ruthless neuropsychologist, was visiting and quickly reduced Penny to tears discussing her father issues and just being there incited Leonard's own parental issues. Seeking solace with each other, Leonard and Penny ended up in her apartment doing tequila shooters and other drinking games. One thing led to another and they were in Penny's bed. Leonard was giddy that this was finally happening and referenced how his Mom would interpret the Freudian implications of what was happening (basically they represented each others parents, Leonard was Penny's father and Penny was Leonard's mother). This disturbed Penny enough to ruin the mood, though the next morning they both silently agreed to just not talk about it.
Also, Sheldon does this many times by knocking on Leonard's door and interrupting with something unimportant. For example: he wants Leonard to participate in a card trick. He also spent some time with Penny trying to decipher the meaning of a tie on Leonard's doorknob, which Penny explained as "Do Not Disturb." Sheldon ended up calling him to let him know "Message received."
When Leonard and Penny end up alone in a hotel room in Big Sur, Raj walks in and climbs into the other bed. He also asks if they want to watch Bridget Jones' Diary.
This is a Running Gag in the season three premiere. Leonard's come home from a long trip to the North Pole, and Penny has missed him very much. While there's no shortage of kissing, it's always interrupted, right up until the end of the episode.
In The X-Files episode 'Small Potatoes' Scully is just about to kiss a shapeshifter disguised as Mulder... when the real Mulder bursts in and kills the mood. However, that moment killer was appreciated by all involved and watching. And in true Mulder and Scully style, they never speak of that moment again (excluding one little teasing remark from Mulder).
In fact, moment killers and Cannot Spit it Out are two of the major tools used to keep Jeff and Annie from acting on their mutual love and UST
Almost every serious romance between main characters in Star Trek is replete with moments where someone phones in and tells one or both to report to the bridge. In addition, the moment killing between Picard and Crusher reached such heights that they eventually hang a lampshade on it by having him literally disappear into thin air just as she's about to tell him her true feelings.
Being Human rather enjoys this trope. While Nina and George are an already established couple, there is a scene in the third series that is just one moment killer after another. They are attempting foreplay and are first interrupted by her hair getting caught on his glasses. Then the pen in his pocket makes it difficult to move. Then Mitchell obliviously walks in, climbs over the bed, takes something off the nightstand, and rushes out. Nina tries to recapture the moment, but George just whines and pouts.
Gilmore Girls had Kirk and his night terrors interrupting Luke and Lorelai's first real kiss.
In the season seven premiere of How I Met Your Mother, Robin is about confess her resurfaced feelings for Barney when his phone rings. This puts a serious damper on the moment, seeing as the caller is Barney's new romantic interest and Robin actually ends up Playing Cyrano for them.
Similarly, in the S7 episode 'Disaster Averted,' we see an almost-kiss in the rain between Robin and Barney interupted by Robin's dad calling her.
In the fifth season finale, after Robin crashes at Ted's after being dumped by Don, the two come close to kissing after having too much to drink while Ted is trying to comfort her. However, at the last moment, Robin accidentally knocks off his baseball cap to reveal his hair, which he had bleached hideously blond on a dare earlier in the episode, causing both of them burst out laughing hysterically. Future!Ted notes that "And that's how dying my hair stopped your Aunt Robin and I from doing something we both would have regretted."
And in the season eight episode "Splitsville", they have anotherAlmost Kiss that was interrupted by - wait for it - another telephone call, this one with the news that Barney accidentally made good on a threat he'd previously made to Robin. No one hates cell phones quite like a Swarkles shipper.
In season nine Ted is trying to hook up with a woman at the wedding and things are going well till she gets a phone call that she was fired from her job as a school teacher because all the kids hated her. Things go downhill from there and the woman quickly becomes a sobbing wreck. Ted then tries to extricate himself from the situation but he keeps missing the right moment and get interrupted every time. Then the woman wants to have sex with him to forget all the bad things that happened to her but Ted is too much of a gentleman and kills the moment himself. The next day it seems that he will be able to hook up with the only other available woman at the wedding when he makes a toast to honor the church minister who just died. However, it turns out that the minister was the first woman's uncle and Ted once again has to comfort the crying woman and give up any chance of having sex that weekend.
During Lucy and Jimmy Moon's first unofficial date, the two are watching a romantic French film and about to share a moment when Eric bounds into the room with his guitar. This was actually a revenge ploy by Mary, who was angry at Lucy for some reason or another.
Happens with these two again in the Valentine's Day episode. Jimmy's about to give Lucy her first kiss when an usher pops in and announces that Simon, Nigel, Lynn and Ruthie were caught acting up and have been kicked out of the theater.
Happens between Maddy and Jonathan in several episodes of Jonathan Creek. Most of them interrupted by someone from the case calling or showing up on their doorstep or a small misunderstanding turned Up to Eleven by Maddie (finding a pulse monitor on Jonathan when they're about to have sex, spotting him in another woman's car on the eve of his birthday).
Late Night with Conan O'Brien had a character played by Jon Glaser who could ruin any moment by saying one word. That word? Pubes.
On 30 Rock, Liz invokes this trope to get in the way of the weird sexual tension between Jack and his mother-in-law, played by Mary Steenburgen. Liz proudly declares that, "All my life, I have been the third wheel that prevents people from having sex." Apparently she was nicknamed "The Blocker" in college.
Diana: Oh, you're still here. Liz: That's what they all say
On Castle, both Castle's mother Martha and Detective Kevin Ryan appear to be separately competing to see who can inadvertently interrupt Castle and Beckett during a warm and fuzzy romantic moment the most.
Martha wins—for all time—in "After the Storm", when she comes home from the Hamptons early...the morning after They Do, thus having Beckett make a mad dash for the closet so she wouldn't find out.
Although the man dying in the swimming pool just before Castle and Beckett were about to go skinny-dipping in "Murder He Wrote" came close to topping Martha.
Batman episode "The Bat's Kow Tow" concludes with Batman and Catwoman Almost Kiss when Robin off screen shouts out something along the lines of "C'mon, Batman! The police are here!" Catwoman, in a contained fury says, "Boy Blunder!"
Doc Martin: Martin manages to muck up the moment with Louisa repeatedly.
House of Anubis: Aggravatingly often, usually something mundane. It's a favorite trick of the writers, and has happened to basically every pairing on the show at least once. Lampshaded by Nina in the season one finale, just before Fabian asks her to the prom.
Nina: Now hurry up before there's an earthquake, or a swarm of locusts, or anything else that stops you from asking.
House of Cards: Remy and Jackie are making out and about to have sex when Remy asks Jackie - an army veteran-turned-politician - about the meaning of a tattoo she sports. He loses his libido when she says she got the tattoo because the pain of it helped her deal with all the people she had to kill as a soldier.
Happens several times in The West Wing- especially between Jed and Abbey (some particularly funny examples are in season 4's Election Day & Process Stories. Josh and Donna have their moments, too.
Death Valley Billy has two of these with Kirsten. Once When the bomb goes off in the station and again when Stubeck "glock-blocks" him by trying to arrest a secret vampire in the station.. Billy is so upset by the first time that his session with the psychologist is all about it. The deaths of 2 colleagues and the serious wounding of another, not to mention having to fight to survive the night don't get mentioned.
Queen's song "Tie Your Mother Down" is about the narrator taking...drastic measures to avoid his Love Interest's family ruining their moment.
The song "Susanna" by Dutch band VOF De Kunst/The Art Company is about a man who is about to get close with his girlfriend (something he has been waiting for for a long time now), but then the moment is interrupted by a phone call from someone who dialed the wrong number. Afterwards, the romantic atmosphere is gone.
A non-romantic but still important relationship moment killer happens in Henry IV Part 1. Prince Hal for the first time expresses that when he becomes king, his friendship with Falstaff will end. Before Falstaff can properly answer that, the sheriff arrives to arrest Falstaff.
Toward the end of Henry V, Henry spends a great deal of of words trying to woo the French princess Katherine who doesn't speak any English. After finally charming her into letting him kiss her, her father and the French and English courts re-enter to sign the terms of peace. Some productions have the couple shoot apart as if they'd been zapped by lightning.
In Act 2 Scene 3 of Othello, Othello is called down from being in bed with Desdemona to break up a fight between Cassio and Roderigo. It's implied that they interrupted his attempt to consumate his marriage.
In On the Town, Hildy and Chip's embrace is rudely interrupted by her roommate Lucy Schmeeler's violent sneezing and inhaler use.
Lucy: Y'know, Hildy, this is just like taking a picture. If I had a camera, I could get the two of you together. Hildy: You could do that by just leaving the room.
In Persona 3, during the Yakushima Island vacation, the Main Character goes out to comfort Yukari after she runs off upon discovering that her father was responsible for creating the Shadow threat the party has been fighting. After a brief and somewhat stormy conversation, depending on the player's dialog choices, the Main Character will move to embrace Yukari... and then the two will fly apart when Junpei shows up to bring them back inside. True to form, Junpei asks "Did I miss something?"
In a cut scene in Max Payne 2, Max and Mona are in an alley heavily making out to the point where Mona is leaning against a wall with her legs wrapped around Max and her shirt pulled up to her neck and Max *ahem* below that, when they hear Mooks yelling and running towards them. They then have to end their previous activities.
In Metal Gear Solid 3: Snake Eater, Naked Snake managed to cock-block himself. EVA moved in to kiss him and was suggesting a little more when he out of the blue decided to offer her a roasted snake, while moving his head away from her.
Later on, he declares his love for her!... except he doesn't:
Snake: I need you. EVA: ... Say that for me one more time. Snake: I need you. I can't pilot the WIG all by myself.
This is eventually spoofed in the memetically famous Hiimdaisy comic: "Eva, I... I need you! (Eva starts to stare and blush in awe) ... TO STOP WHINING AND FLY US OUT OF HERE!"
Mass Effect 1 - Shepard and your chosen Love Interest are getting quite close (should you pursue the romantic subplot between them) when Joker interrupts. Shepard can accuse him of doing it intentionally.
Also, in the third game, if neither Garrus nor Tali was romanced, Shepard will walk in on them getting quite cozy near the end of the game. They stammer that Garrus's mandible just got caught on her helmet.
At the end of Uncharted: Drake's Fortune, just as Nate and Elena are leaning in suggestively for a kiss, Sully comes out of nowhere and says "You two got a funny idea of romantic!" therefore breaking up the romance... and making it a dreaded Almost Kiss. Nice job, Sully.
Jak and Daxter: Daxter. Daxter Daxter Daxter Daxter Daxter. Turning a kiss into an Almost Kiss once would be forgivable, but doing it twice? Thankfully, not only does Jak get his revenge in Jak 3, but at the end of Jak X Daxter Lampshades this with "Would you just kiss her already? Sheesh!"
Ghirahim appears to love destroying any happy moment between Link and Zelda in The Legend of Zelda: Skyward Sword. First he knocks Zelda out of the sky with a black tornado just as she's about to give to Link what appears to be a love confession. Then he kills the second reunion (the first being halted instead by Impa) they make at gate of time by charging in and attempting to kill both Impa and Zelda. And then he shows up after the Imprisoned is killed and Zelda is released from her self-imposed seal to cockblock the two again by kidnapping the poor girl and running off into the Gate of Time.
Becomes a running gag in Ace Attorney, when Detective Gumshoe walks in, accompanied by a loud "Thump" and exclaims "Hope I'm not interrupting anything!" Cue the icy stares and Gumshoe sulking off. After which Phoenix will promptly call him over. It was a running gag in the bonus fifth case where Gumshoe would then retort "You're doing this on purpose, aren't you? Making a gumshoe run around while on duty! And on top of that you drag me here! I've seen happier people at funerals!"
Final Fantasy IX has one scene involving Steiner and Beatrix together... which gets wrecked when Baku walks into them, sneezing loudly.
The Curse of Monkey Island - Guybrush has just proposed to Elaine, and put the engagement ring on her finger, when Wally appears and innocently informs them that the ring has a huge voodoo curse on it. Elaine is not happy.
In MOTHER, right after Ninten and Ana confess their love for each other, Teddy bursts in and a giant robot attacks them, severely injuring Teddy. Real moodkiller there.
Tenebrae: Ah, two young hearts all aflutter. How sweet.
Emil: "Aflutter"? Who says stuff like that anymore?
Tenebrae: I do. You got a problem with that?
Emil: *laugh* You're funny, Tenebrae.
Marta: Way to kill the moment, you two...
Happens a couple of times in Black Sigil. Every time Kairu and Isa seem about to kiss, Juji comes in and breaks them up.
In one of the street cases of L.A. Noire, Cole Phelps become one of this when the suspect and his girlfriend is having a romantic moment.
In Solatorobo, Red does this to Dade and Vanille. His sister Chocolat also does it accidentally to Red and Elh when she tells a group to Leave The Two Love Birds Alone too loudly and the lovebirds in question overhear her.
Jenon has an unfortunate tendency towards this in Blaze Union. Early into the story, there's a scene where protagonist Garlot and his childhood friend Siskier have a heart-to-heart while waiting for their enemies to walk into their trap—and right when Siskier has finished giving Garlot some much-needed encouragement, Jenon comes charging in with the announcement that it's time to fight. And then pauses to ask Siskier what's wrong and why her face is so red. Siskier is not amused.
Much later, in the final chapter of the canon route, there's a scene after the battle of the day has been won where Gulcasa and Nessiah take a few moments to praise each other on their good teamwork. Their happiness is, of course, short-lived: Jenon comes charging in to interrogate Gulcasa with no small lack of subtlety or sensitivity, leaving him very confused and upset. Nessiah then cuts in to inform Jenon that now is kind of a bad time, and proceeds to drag Gulcasa off so that the two of them can have peace and quiet. Among other things, this scene is very much meant to be a more somber Call Back to the early one between Garlot and Siskier.
In yet another scene from the canon route (taking place before the Gulcasa and Nessiah one), Siskier comes out to chat with Garlot one night while the latter is worrying about the future, and over the course of their discussion, she comes very close to confessing her feelings for him several times but continually cuts herself off. Just when Garlot has finally figured out that something is weird about the way she's acting, there's a surprise attack from the enemy.
Scooter hilariously murders a touching family moment between Ellie and himself in Borderlands 2. Ellie and Moxxi, Scooter and Ellie's mother, have argued severely in the past, disagreeing to the point of both women living on different parts of the planet. When things go bad towards the end of the game, however, Ellie asks Scooter to tell their mother that she loves her, but Scooter says that Moxxi already knows and always knew. It's really rather sweet and shows that for all their personal flaws, they're still perhaps the most loving family on Pandora. Then, Scooter returns to normal:
Scooter:"CATCH-A-FAMILIAL-RECONCILIATIOOOON!" Ellie:"Why you gotta keep doing that?!"
Later, in the epilogue to Tiny Tina's Assault on Dragon Keep, Marcus finishes his story in an uncharacteristically schmaltzy, emotional way...
Claptrap:"I love you guys." Marcus:"...and then Claptrap said something stupid and ruined everything."
One lesbian Touhou doujin completely hilariously defies this trope. Satori and Koishi share a moment, until Koishi basicly asks Satori to make love to her. Satori, apparently fully Genre Savvy, rushes to the door and locks it up, before taking her on the offer.
The Judge does this many times in Ace Attorney. Many a tense moment is spoiled by a him misunderstanding words or saying something stupid. For example when Edgeworth is saying about how The Chief of Police Gant used Lana as his puppet and the suspense music starts up, only for the music to stop abruptly as the Judge says this stupid remark:
"You mean despite his manly structure and power, The Chief of Police...likes to play with puppets?!"
He does however a lot of the time correct himself like in the above example:
"Oh wait, you mean someone who uses someone else! Never mind."
In the Fate/stay night games, Sakura tends to walk in at bad moments. This is especially bad in Fate/hollow ataraxia where she manages to walk in on just seemingly every scene that Shirou and Rider have together. Perhaps justified though—Sakura is Rider's Master, also likes Shirou, and the few times she doesn't walk in, Rider and Shirou tend to end up naked.
Homestar: Ah, good evening ungodly couple, my name is Waiter, I will be your Homestar for this evening. Can I start you two off with a glass of "Breaking Up", or perhaps "Never Seeing Each Other Again" with capers?
Forgath has become this in Goblins whenever he shows up as Minmax and Kin discuss their feelings… and lately as the two are sharing a very tender hug after Minmax saved Kin from imaginary Goblinslayer/the mysteriously growing forest.
Casey and Andy, Strip 627: Andy pops in to inform Casey of the arrival of Jenn's time-traveling daughter, and the necessity to embark on further temporal misadventures to save the timeline… while he's in the middle of proposing to his girlfriend. Of course, Mary is very understanding, and even lets Casey go off with Andy to save the timeline.
Chapter 18 of begins with Kat walking in on her parents as they're getting intimate. Much cheer was had when they carried on after she had left the room.
Also, in Chapter 30, with Parley having admitted her love for Andrew, as they're moving in for their first kiss, Antimony interrupts them by continuing the discussion they were having beforehand.
Then seconds later does it again when the moment is in danger of reestablishing itself. Kat has to drag Antimony off.
Misfile - Rumisiel plays the Moment Killer on Ash and Em in an early strip, sending their relationship straight down Belligerent Sexual Tension alley. And here we have Ash and Em having a significant moment, with Em just on the verge of saying that... "Y Helo Thar, Missi!"
El Goonish Shive had this often, usually with Sarah doing the moment-killing — and occasionally realizing that she'd just killed a moment. Also lampshaded in the process of aversion when Tedd asks Grace why she's leading him away from Ellen and Nanase as if they need privacy for some reason.
The Demonic Duck deliberately interrupts Justin and Susan during the party using his illusion powers. Afterward, they're both grateful the "light bulb burned out".
In 8-Bit Theater, Black Mage accidentally killed his own moment. The one time when it seemed he might be slowly winning the heart of White Mage, he casually let it slip that his Hadoken siphons love out of the universe every time it's used... and that he sacrificed several children to obtain the spell. She didn't take it too well. Tough luck for BM, but if he ever reads this page, he'll feel better knowing he killed something.
Except that he would probably want those moments back. And this is not the only time Black Mage cockblocked himself either.
In the chapter "Summer Vacation", Zoe feels attracted to Torg after he does something heroic (if stupid). Even Kiki comments that they're going to smooch. But when Zoe starts telling how brave she thinks he was, he obliviously says that if she was impressed by it, another woman he has a crush on is "going to flip", and goes to call her. The moment is killed so thoroughly Zoe stops showing any such inclination for years.
Later, having realized he's in love with her, Torg tries to win Zoe's heart with a giant bejewelled necklace he found in a pyramid as a Christmas present. She's quite taken with the gift, until she puts it on and it turns her into a camel.
Subverted in "Love Potion," when Torg and Zoe look at each other by accident while they think they're under the influence of a potion that makes people madly attracted to the first person they see. As they're staring at each other, Gwynn pops up to tell them the potion's effects have worn off. After she leaves, Torg finally asks Zoe out and she readily accepts.
The big moment killer comes in the same chapter, during said date. Just as he's contemplating leaning over and kissing her, he suddenly finds lips touching his - but they belong to an immortal assassin who is extremelyobsessed with him. To protect Zoe, he has to insult her and then laugh it off when said assassin kicks her in the face, right before dragging him away to get married. Epic moment kill.
Done for all sorts of drama in the "bROKEN" Story Arc. Zoe has just realized that Torg's in love with her, and, to her own amazement, that she loves him back. And Torg's rushing to her location right at that moment. Then the assassin mentioned above sets Zoe on fire, seemingly killing her just as Torg arrives on the scene.
Deliberately set up in Blip. When Hester gets set up on an unwanted date, she arranges for her friend K to "accidentally" run into them and act as a third wheel for the remainder of the date.
In this strip Florence and Winston are about to kiss, but are interrupted by a watching young boy crying out "there's a man outside who's gonna kiss a dog!" (Florence is an uplifted red wolf, whereas Winston is a human male.)
Dubious Company has a moment that acts as both a romance killer and a heroism moment killer. Walter and Tiren are being chased by Mary, Gary, and Marty and reach a cliff. Walter rips off his shirt (he has wings) and grabs Tiren. Meanwhile, the rest of the crew is climbing up said cliff. Leading to this exchange. Did I mention Tiren is Walter's first mate?
Knights Errant: Wilfrid the Heartless is the killer of many things- "the moment" among them. Like here, where he kills the moment so hard that the moment's ancestors probably felt it.
In Sinfest, whenever Slick and Monique have a genuinely tender moment, it will usually be ruined by Slick's stupidity or Seymour showing up and bothering them.
This has become a Running Gag (and an occasionally cruel one) in Ménage à 3, with Zii constantly—and usually unintentionally—cockblocking Gary.
In the fourth book of Shadow Of The Templar, Jeremy, normally calm and emotionally unaffected, suddenly kisses Simon passionately and seems to be about to tell him something important. Of course, they're interrupted before he can get it out.
In Spoony's Vlog/Review of the New Moon movie, he comments on how Bella and Jacob are about to kiss several times before something stupid happens, such as, as he put it, a guy runs in yelling "Hey you guys I made muffins!!".
A variant of this trope occurs in SOTF-TV, where, after a traumatic first day, Amber Lyons and Sterling Odair start to get... "intimate". Unfortunately, however, each team has a mentor which can give advice through the collars. Hilarity Ensues.
Jared Clayton: "Less fucking, more playing. Keep it in your damn pants and maybe watch your fucking backs for once? Wanna wind up like Anthony? Thought not. Wanna argue? I won this game. Fuck you. You have a godsend of a mentor, and he's telling you to wise up."
In The Nostalgia Chick's countdown of songs about sex, the Chick manages to kill the moment herself when, after Todd in the Shadows agrees to sleep with her (out of boredom) she puts on one of the songs from her list and he immediately runs away.
There's also Mignon, her puppy, who likes to nom on her mistress even when Dark Nella is being all threatening.
A variation of this, but in Two Best Friends PlayThe Walking Dead , Matt decides to have Lee shoot Duck. Normally, people are saddened by this, even some people who didn't like Duck, but then Matt says his favorite phrase: "SEE YOU LATER, FUCKER!"
Batman: The Animated Series has a scene during Two Face's Two Part Start of Darkness. The scene where he is looking at a photo of him and Grace and trying to decide whether or not he should go to her is incredibly touching... until you spot the bank card with the name "Two Face" on it and realize he must have walked right into a bank and opened an account under his villain identity.
This is actually quite a common occurrence in Teen Titans, whenever two (or more) characters share a quiet moment, be it romantic or otherwise. For instance, when Starfire was cheering Cyborg up about not being normal at the end of "Deception", the rest of the Titans show up to wrestle Cyborg into a pink dress as an "initiation".
In "The Earth King", the group was parting ways for a little time, and Aang wanted to confess his feelings to Katara. Just as he said, "I kinda want to tell you something..." Sokka swings his arm around him and excitedly talks about where they are going.
Earlier Aang finds himself in the rather odd situation of having the person he's trying to talk to be the moment killer: when he first tells Katara how he feels she's so completely not paying attention that she actually shushes him.
Aang managed to do a pretty impressive job of moment killing himself in "The Cave of Two Lovers."
"I'd rather kiss you than die. That's supposed to be a compliment!"
Zuko and Katara have a gentle moment where Katara was pondering whether to use her healing powers on Zuko's scar... when Aang bursts through the cave wall to come to the rescue. Word of God has repeatedly said that nothing romantic was implied in that scene anyway, except maybe a cruel "never-going-to-happen" Ship Tease.
Zuko also picks a very bad time for a chat with Sokka, although this doesn't actually kill the moment so much as delay it for a few minutes.
And even later when Zuko sits between Aang and Katara when Aang wanted to sit next to Katara. Zuko is really bad at this. His Fan Nickname is Prince Zuko: Master Cock-blocker.
Runs in the family: Azula does it to Zuko and Mai during their sunset picnic. Azula does it on purpose. Zuko simply doesn't think. (He's older and more experienced than most of the kids on the show, it's just that he's a bit too self-focused to realize other people might have relationships outside him.)
In The Legend of Korra, Korra makes a second Anguished Declaration of Love to Mako after he accuses her of dating Bolin just to annoy him. Then she kisses him and he seems pretty into it . . . until they see Bolin holding a bouquet which was clearly meant for Korra and bawling his eyes out. Not that that kiss was going to end well anyway.
Played with on Code Lyoko. After returning from a school break, Yumi wanted to talk to Ulrich about their UST. No less then three times in 10 minutes, as they tried to have that moment, they were interrupted. When they finally get the needed 30 seconds, Yumi then gives him the dreaded Just Friends line. Ouch.
In Justice League Unlimited, Flash managed a dramatic moment killer: the league makes a perfect, epic entrance and the awe of the moment gets Narmed by Flash shouting "Ta da!" More traditional examples happen to moments between Green Lantern and Hawkgirl. A few of these happened to Batman and Wonder Woman. One time, they were discussing about their potential relationship when an alarm sounded off.
Joker manages to do this between Hawkgirl and Green Lantern... Literally. GL got better.
Wade does this a few times in Kim Possible. Apparently it was funny according to the writers.
In the episode "A Flight to Remember", where the characters travel on a cruise spaceship:
Leela: Looks like everybody's got somebody. Except me. Fry: And me.
(they Almost Kiss, when the ship shakes and they fall over)
Leela: What was that? Oh, my God! We're heading straight into a black hole. Fry: Talk about a mood killer!
In the episode "Parasites Lost", Fry himself kills the moment. First, he runs away to get rid of the parasites, hoping to prove that Leela loves him and not just what the parasites did for him. When he came back, and Leela was rather miraculously still in the mood, he managed to tick her off by bringing an old girlfriend into the conversation. Fry would rather win her over while remaining who he is instead of letting the miracle worms keep turning him into Batman.
One of the most epic moment killers ever involved an episode where time would skip forward randomly, such that certain things would happen and the character never remember how they got to that point. Fry had managed to convince Leela to marry him in one of those skips and she divorced him during another, so he tried to figure out what he did to convince her in the first place. As it turned out, to stop the time skips they had to drop several dozen stars into a black hole so it wouldn't interfere with the rest of the universe. Using the star moving device, Fry spelled out a declaration of love using the stars themselves. Before he could point it out to Leela the Doomsday Device sucked all the stars into the black hole.
Cody from Total Drama Island constantly kills Gwen and Trent moments by trying to win Gwen's affections, he even manages to pull this off in the theme song.
In Superman: Brainiac Attacks, the titular villain is the moment killer for Clark and Lois. Let's face it, all supervillains seem to have perfect timing for moment killing...
In the Hulk vs. Wolverine this seems to be Deadpool's role, though he kills drama rather than romance. For example, as the Weapon X members resolve to hunt down Wolverine and there's the traditional menacing shot of the team assembled and ready for violence, Deadpool shouts, "Strike a pose!"
In The Fairly Oddparents, "Wishology" Part III had a Running Gag about Timmy and Trixie trying to kiss, but a different character would interrupt them each time: first Mark, then Mr. Turner, then finally Jorgen, who may be the worst (or best, depending on how you look at it), since he flat out tells Timmy he's wiping everyone's memories, effectively hitting a Reset Button of the relationship.
Parodied in South Park; for most of the series, every time it's even theoretically possible Stan and Wendy might be on their way toward having a moment, he throws up. Usually on her.
"A Jones for a Smith": A crack addicted Stan ruins Steve's chance to hook up with a beautiful girl whose father is willing to let Steve sleep with her.
In one episode Stan and Steve are having a really sweet moment, then Steve says: "Are we having a father-son moment?"
In the "Teen Talk" episode of Beavis And Butthead, Beavis and Butthead are about to hook up with Lolita and Tanqueray when Captain Dick Jackman cockblocks them and the two girls end up making out with two members of the production crew instead.
Happens on Kick Buttowski between Kick and Kendall. They're having a moment... that really only seems to lead to one thing, which apparently a member in the audience picks up on and thus shouts "KISS HER!", to which the moment is ruined and the pair feels disgusted.
Lampshaded in the ThunderCats (2011) episode "Song of the Petalars" Lion-O and Cheetara are sharing a tender moment alone by a campfire, when Snarf jumps onto Lion-O's face.
The Simpsons: In the "New Kid on the Block episode, the Simpson's babysitter, Laura Powers and Jimbo Jones are making out at second base when Moe Syzlak charges into the Simpsons' house to threaten Jimbo with a rusty and dull butcher knife in retaliation for making prank calls that Bart made in his name, causing Jimbo to break down in tears. Laura then dumps him.
In Gravity Falls, Grunkle Stan interrupts a man who is in the process of proposing, in order to crack a joke about how terrible marriage is.
Reboot, in addition to the moments listed under Almost Kiss, there was the reunion between Bob and Dot after almost an entire season of being separated. That got interrupted by Mouse getting to Bob first and passionately kissing him in front of Dot, which killed the moment and led to a bunch of awkward almost hellos and almost handshakes.
Comedian Pablo Francisco describes this trope perfectly in one of his sets.
In Patton Oswalt's comedy album Werewolves & Lollipops, Oswalt is building a serious moment about birth control and having an intimate relationship when... this happens.
General news reporter/news anchor Wendy Rieger when interviewed on a college cable channel said that one thing that annoys her is when fans bother her for an autograph and end up twatblocking her when she's trying to pick up guys.
This trope was invoked by a group of guys none too happy with their friend ditching them to try and have sex with a girl. So they set about sabotaging him on facebook in the most blatant way possible.◊
I though you were better than claiming "I have this shit in the bag."
Ask any parent how many times they've been interrupted. Children are Master Moment-Killers.
Leaving the TV on during romance can lead to this. Bad commercials can kill the moment like they were paid to.