The primary instincts of all creatures— sex and death. If you can combine the two they become a bigger selling point. We're not talking about Death by Sex or Interplay of Sex and Violence but something else.
Though not exactly graphic, the Kiss of Death is still sensual, seductive, and very, very deadly. While a character may be anxious about administering the Kiss of Life, nobody is shy about giving the Kiss of Death. This may be because Evil Is Sexy or the more practical reason — once somebody catches onto what the kisser is going to do, they'd run for the hills. This is a favorite weapon of The Vamp.
The Kiss of Death comes in many varieties, including: hypnosis, narcotic effect, and sucking out the soul of the victim, which may or may not result in death, depending on the story.
In addition, the Kiss of Death can also be a symbolic gesture — the kiss itself does not bring death or harm, but the person who receives it knows that his days are numbered. The trope is named for the kiss from The Bible with which Judas Iscariot identified Jesus among his apostles and thus betrayed him to the Romans, making this Older Than Feudalism.
The PG rated form of Out with a Bang. Not to be confused with Last Kiss, though it can overlap if the right circumstances are met.
See also Kiss of the Vampire, where a vampire's bite is both pleasurable and deadly.
This is a death trope, so Spoilers ahoy.
Fuka from a Naruto: Shippuuden filler arc has a technique that can literally kill the victim with a kiss (she asks if the victim wants French or soft) by sucking out their soul and their life force. She uses this to steal techniques and elemental affinities (Fire, Wind, Lightning, Water, Earth).
Ran from Urusei Yatsura has the power to suck the youth from someone by kissing them. She usually tries to use the power on an unsuspecting Ataru, who just thinks she liked him. She can also reverse the process with another kiss.
Later in the manga, her "youth-stealing kiss" gets nerfed by the Rule of Funny, as all it does is essentialy making the victims act like stereotypical Japanese senior-citizens.
Used in Read or Die against Yomiko by Nancy, when it turns out she was The Mole for I-Jin leader Ikkyu (specifically, the lipstick mark it left had something that can affect her when activated by a remote). It doesn't kill her, but she does get knocked out for quite a while.
From Basilisk, this is Kagero's primary ability. Whenever she gets aroused, she starts breathing out a deadly poison, thus, whoever she kisses, she kills. And in fact this is how she kills Koushirou Chikuma: since he's blind, Saemon confuses him via imitating Akeginu's voice, then Kagerou slips him a deadly kiss. Later, she tries to use this ability on Tenzen alongside a Neck Snap but it fails since his powers is coming Back from the Dead, and at the end only Oboro's Mystic Eyes could stop her from poisoning Gennosuke after Tenzen had driven her insane through Cold-Blooded Torture.
Love Hina: Naru Narusegawa, when possessed by a demon sealed within a sword, was also implied to have gained the ability to sap people's life force by kissing them.
In Dokuhime to kiss or come into any contact with a Poison Princess is deadly.
In Yu-Gi-Oh! 5Ds Carly (as her Super-Powered Evil Side) made Jack think that he had lost their duel and that she had done this to him, killing him with her kiss and turning him into a Dark Signer like herself (and that the world had been turned into a Hell that they could rule as king and queen). Possibly, she was indeed capable of doing this; however, it was all an illusion meant to distract him from the actual move she intended to use to finish him off, and he snapped out of it before she managed it.
Sorta used in Sailor Moon. One of Minako/Venus's light/energy attacks is called "Love and Beauty Shock" and she delivers it via blowing a kiss to her enemies.
In Campione!, Athena can do this by breathing the "Winds of Death" into the other person's mouth.
Kiss of Death is also a move in chess. It means a moment where a Queen is right next to the opposite King, protected by a Mook (or the King) of her own army.
Rogue's power in X-Men is stealing other people's life force and abilities by touching them. She first discovered her power by kissing her boyfriend for the first time, putting him in a coma. While any skin-to-skin contact will do the trick, for a long time her preferred means of using her power on others was to kiss them (at least men). She hasn't done this in awhile, however. Taking off her gloves has long been a sign that she means business.
Poison Ivy of Batman. Like Rogue, she can use her powers through any skin contact, but enjoys doing it by kiss.
She can not only kill with her kiss, she can occasionally hypnotize people with it. In the Batman: The Animated Series episode "House and Garden", she did this to get out of Arkham, tricking her psychiatrist into accepting a kiss, making him her slave, and then ordering him to write her a clean bill of health. (Then pretending she married him; she almost had Batman himself fooled and might have gotten away with it completely if the same psychiatrist had not been one of Robin's college professors, and Robin knew that the guy's former wife had custody of the two sons that Ivy claimed he had - and that his children were actually daughters.)
The original X-Factor (which was actually made up of the original roster of the X-Men) dealt with a one-shot mutant villain called Infectia who could mutate humans and turn them into monstrous slaves (who eventually died) by kissing them, and it seemed kissing may have been a prerequisite. (She used her power on plants, and tried to use it on their living, sentient Ship, each time using her kiss.) Curiously, trying to use it on the Beast had an unexpected effect (most likely because he was another mutant), restoring his intelligence and furry form that had been stripped of him by Apocalypse. (Much later, he tended to her as she was dying from the Legacy Virus, seeing as he kind of owed her one.)
The Mighty Thor nearly caught one from Hela, but she was so touched that Thor would have sacrificed himself for his girlfriend, that she let both go scot-free.
Films — Live-Action
Catwoman from Batman Returns stuffs a taser into her mouth (non-shocky end in), grabs the power cables of a generator, and gives a kiss to Corrupt Corporate Executive Max Shreck. This, naturally, does not end well for Shreck.
In Lifeforce, a naked space vampire woman killed (and zombified) a man with a kiss by sucking out his lifeforce...therefore, the name of the movie.
In Elektra, Typhoid gives the eponymous character a lesbian Kiss of Death which infects her with a deadly virus, complete with slow motion falling over and a sickly CG effect moving over her skin. She gets better.
Kill Bill has a very graphic version of this in the Dude, She's Like in a Coma scene: the guy who's going to rape the Bride gets his tongue ripped out when he tries to kiss her.
In Species, Sil kills someone while kissing him by sticking her tongue out through the back of his head.
In the Hong Kong action movie Naked Killer, the lesbian assassin kills her former mentor/lover with the poisoned lipstick trick.
Subverted rather creepily in The Mummy Trilogy when Imhotep, who is mostly regenerated at this point, happens upon Evey while she is sleeping and kisses her. While they kiss, his face rots away until his whole mouth is in it's former state. She wakes up while this happens. Sort of like a reverse kiss of undeath.
Rogue's powers absorb the life force of anyone she touches. She has no control over this ability, and it first emerged while she was kissing her boyfriend, putting him into a three-week coma. In the second film, trying to kiss Bobby has a similar effect, but they end the kiss before any real harm comes to him.
In The Wolverine, Viper’s venom powers allow this. She uses this to dispose of a Japanese man who mistook her for a prostitute.
In Kull The Conqueror the Red Witch gives such a kiss to Kull, though taking a liking to him, she does not give him the fatal version. (Apparently she could have if she wished). At the end of the movie, she beckons to him with a promise of a kiss and Kull gives her his own kiss of death, forcing the Breath of Valka into her body.
In the theme song of the James Bond film Goldfinger, girls are warned to beware of "The Kiss of Death from Mr. Goldfinger".
Most forms of the "Vampire's Kiss".
A Polish folksong known as 'The Kiss' tells the story of a young girl who gets kissed thrice by an unknown man (strongly hinted to be some form of a demon). She dies later that day, after relating the event to her mother.
The Draghkar in The Wheel of Time kiss their victims, consuming their souls the first time and their lives the second.
The Harry Potter series had the Dementor's Kiss, in which the victim's soul is consumed. Unusually for this trope, though, this particular example was never portrayed as being sexy at all. The victim technically lives, but only in a braindead state.
For as long as she can remember, the female protagonist of The Raven Cycle has been told by everyone in her psychic family that if she kisses her true love, he will die. She gets pretty sick of hearing it after a while.
In the Star Wars Expanded Universe novel Darth Bane: Path of Destruction, Bane's sometime helper Githany attempts to kill him by means of poisons applied to her lips. Upon kissing him - more than once, which ups the dosage, she gets out of sight to take the required antidotes. Bane detects and counters the poison with the Force...except there were two poisons, an easier one to lull him into thinking he was now safe, and a harder to detect one that nearly kills him.
Though she doesn't give it, the eponymous villain of The Snow Queen can kill with three kisses; the first two mess up your head.
After Mina from Dragonlance allies with Chemosh, the god of death, he gives her the power to kiss people and turn them into a more good-looking type of zombie. They don't look dead, but technically, the kiss does kill them.
In the Michael Crichton novel Prey, Julia kills multiple people with a kiss that transfers the deadly nanobots into them, almost killing her husband, Jack, once. She later begs Jack to "save [her] babies" with MRIs (the magnets kill the nanobots), telling him she kissed them too. It's not quite sexy, but it does still kill.
In Neverwhere, Richard narrowly escapes having all his body heat siphoned away by the Velvet named Lamia.
The Dragon of Jennifer Morgue, by Charles Stross, has a soul-eating daemon bound to her. The means of operation is more of a bite than a kiss, however.
In The Dresden Files, Thomas Raith has stated that Lord Raith, Thomas' father and the current king of the White Court vampires, is the one who invented the Kiss of Death. Whether or not any other White Court vampires can do this remains to be seen.
"[...]That whole kiss-of-death thing in The Godfather? He was where that phrase originated, only for him it was literal." "Really?" "Supposedly. I've never seen him do it myself, but Lara has, plenty of times. Madeline once told me that he liked to open conversations that way, because it made sure he had the complete attention of everyone still breathing."
The reason Thomas has never seen the ability in action, incidentally, is that Harry Dresden's mother, Margaret LeFay McCoy, neutered Lord Raith's ability to feed, preventing him from restoring the power he needed to use this ability.
In addition, the Red Court vampires have a drugged saliva which is addictive and keeps their victims from struggling before they feed. They call it their Kiss, which Harry lampshades as sounding sexier than "narcotic drool."
In Nathaniel Hawthorne's short story "Rappaccini's Daughter", the titular daughter herself is poisonous, and won't let her suitor kiss her because she knows that would kill him. After spending enough time with her, however, Giovanni also becomes poisonous.
Friedrich de la Motte Fouqué's Undine, bound by the rules of her mermaid people, has to kill her cheating husband, but since she still loves him, she is happy to oblige as he asks her if she could do it with a kiss.
In Hardwired by Walter Jon Williams, "the Weasel" is a weapon which shoots out of your mouth; it is used to kill with a kiss.
C.L. Moore's Jirel of Joiry is a feudal warrior maiden. In the story "Black God's Kiss" Guillaume the Conqueror besieges and captures Jirel's castle after a prolonged fight, kills her retainers and captures Joiry herself. He tries to force a kiss upon her whereupon she sinks her teeth into his neck, barely missing the jugular, and later she escapes from the dungeon where she was held. Determined to find at all costs a way of destroying Guillaume, Jirel enters a dark underground world, braving countless dangers, monsters and perilous black magic. By kissing the statue of a sinister black god she gains the power of giving Guillaume a Kiss of Death, returns to the castle, kisses Guillaume and has the satisfaction of seeing him immediately die in great agony. Only when seeing him dead does she realize that she had been passionately in love with Guillaume all along and that now he is dead "the light had gone out of her world" - and she bursts out bitterly crying for the beloved enemy she had killed.
In Those That Wake's sequel, What We Become, the Old Man kisses Rose to extract the neuropleth from her, which would doom New York and the world.
In the Sime Gen series of novels, humanity has split into two races, the Gens that produce selyn, and the Simes, who do not make their own and must take it from Gens to live (which is fatal if the Gen is at all afraid of the Sime). Simes draw selyn by wrapping their forearm-tentacles around the victim's own forearms and then making lip contact.
Lex had a fiancée whose exposure to kryptonite while she and her boyfriend were in coitus gave her the power to hypnotize men (for the duration of one command) with a kiss.
Also, Maxima's kiss in this verse is highly toxic. Her main motivation is to find a man who can survive it. It ends up being Clark Kent.
In Firefly, Saffron knocked out Mal with a poisonous kiss. Inara was also temporarily paralyzed from the soporific lipstic left on his lips, when she, relieved that he was only unconscious, impulsively kissed him. Of course, after he wakes up, Mal assumes what any guy would assume and thinks Saffron also seduced Inara, who is too embarrassed by the whole thing to correct him.
In "Inca Mummy Girl" from Buffy the Vampire Slayer, the mummy steals the life of various men in order to keep herself alive.
In Torchwood, Captain John Hart has "paralyzing lipgloss". It's a kiss of death because if you aren't treated for it within two hours, your major organs shut down.
In the Doctor Who episode ''Let's Kill Hitler", River has one of these for the Doctor. She later has a change of heart and resurrects him.
In The Dresden Files, vampire saliva contains a narcotic that's powerfully addictive when absorbed through the skin (or ingested). Preferred delivery method? A kiss.
In The Sarah Connor Chronicles, Catharine Weaver, disguised as a different beautiful woman, seduces a victim, then sends a liquid-metal tentacle down his throat to strangle his heart through his esophagus and kill him.
Gilligan's Island episode "The Invasion". During a dream sequence where Gilligan is a secret agent, Ginger (as an enemy agent) tries to kill him with poison lipstick.
Get Smart: A KAOS femme fatale uses poisoned lipstick to kill Max, but he's wise to her and uses...fake lips.
Big Wolf on Campus takes its usual sober, low-key approach to the subject: Sloane the assassin blows a storm of projectile Kisses of Death at our heroes.
The X-Files: "2Shy"'s Monster of the Week uses kissing as a pretense to regurgitate acid into his victims, pre-digesting their flesh so he could suck out their fat.
In Dark Angel, Diamond kissed the man who had her infected with a terminal disease, passing it onto him. Since she's a lesbian, he's also the first man she's ever kissed.
The Nine Lives of Chloe King feature a race called the Mai. The Mai are only allowed to be intimate with other Mai and the results can be deadly for humans. Unfortunately, Chloe doesn't find this out until after she's kissed a human.
H2O: Just Add Water had a one off. Rikki lost control of her heat powers and nearly boiled Zane alive the first time they kissed. He was knocked unconscious and left with red skin for a few days, but it's implied how dangerous the situation could have been.
Almost a decade before The Sarah Connor Chronicles example above, in the music video for "The World is not Enough" by Garbage, a robotic Shirley Manson (who would go on to play Catharine Weaver) kills a test subject by burning him to death through kissing him. "She" then kills the original Shirley Manson the same way, and then explodes during a packed concert.
Myth and Religion
In Jewish tradition, God honored Moses, Aaron and Miriam by taking their souls with a kiss rather than by sending the Angel of Death.
Succubi/Incubi in D&D (all the way to the 1st Edition) have an energy drain attack delivered though either a kiss or a hug. It takes more than one to kill someone (frequently, eight or nine by the time the players are high enough level to encounter one), though. The kiss often has a suggestion with it, to convince the victim to keep kissing the demon.
Nereids in some editions can drown a man who kisses them, but a nereid usually only does this to someone who has the nerve to force a kiss from her. (Or to possibly to someone who steals the shawl that acts as her Soul Jar; a nereid can be Made a Slave by anyone who succeeds in taking it, but that person must be ever vigilant, as she can be cunning in trying to get it back.)
The darklord Ivana Boritsi of Borca in the Ravenloft campaign setting possesses this ability (due to various types of poisons applied to her lips). She is explicitly so toxic that she can kill even creatures immune to normal poisons. She also employs a team of enforcers called the Ermordenung who are given a lethally poisonous touch via an alchemic process known only to her (the leader of which was her best friend as a child); they only need to touch a victim with bare skin to kill them, but a kiss (their preferred method of killing a victim of the opposite sex, usually through deception and seduction) is the deadliest method of doing so.
GURPS: Ultratech advises using the Ripsnake (a mechanical weapon that shoots out of your mouth) while kissing.
Warhammer has the Dogs of War character Lucrezia Bor-I meanLucrezzia Belladonna, an expert with poisons and toxins, including poisoned lipstick. One story has her kiss the tip of a knight's lance, and his unhorsed opponent dying within seconds. When asked if the lance was poisoned, she replied that she had just kissed it and she didn't feel at all unwell...
In Kander and Ebb's musical version of Manuel Puig's Kiss of the Spider Woman, the titular (imaginary) character kills with a kiss. The hero, a prisoner in a hellish Argentine jail, sees her whenever someone around him is poisoned or tortured, and worries that she will come for him next.
In the Austrian musical Elisabeth, Death is a major character. He is made of this trope.
Planescape: Torment features a succubus character named Fall-From-Grace, who (as is normal for her species in Dungeons & Dragons canon) can drain the life from her victims by kissing them. However, as a reformed succubus, she is reluctant to do this except in a dire situation (though the definition of a "dire situation" is whenever the player directs her to, considering she has the kiss as one of her attack commands). Whenever the protagonist speaks to her, you have the option of having him kiss her if his Wisdom score is low enough; due to his ability to come back to life every time he dies, it's only a temporary setback if you choose that option, but you quickly learn not to do it again.
Karim in Eternal Darkness Sanity's Requiem suffers from this fate. Interestingly, it's something he needs to do in order to be able to protect the artifact.
Mortal Kombat is probably the biggest Trope Codifier here, where several characters use this as a Fatality. Sonya Blade blows her kisses and they either burn or eviscerate the enemy, depending on the game. Kitana and Tanya directly kiss the enemy on the head or the lips, causing them to either swell up and explode or twist in several painful ways...then explode, though it would have been arguably more gruesome if the opponent just fell to the floor a twisted, screaming mess.
Pokémon. Lovely Kiss (which puts the opposing Pokémon to sleep), Sweet Kiss (which confuses the opposing Pokémon), and probably a few others. Though they're not really Kisses of Death.
Generation VI introduces the movie Draining Kiss, which actually does damage and absorbs energy from the opponent.
In Devil May Cry 3, the vampire Nevan does this if you don't run away quick enough, making some fangirls commit suicide in order to see Dante kiss someone. If you have enough Devil Trigger, you don't have to retreat - she can't steal a demon's Life Energy, and she's a sitting duck while she's performing the move, so when she gets close enough hit the Devil Trigger and smack the hell out of her.
Subverted in Metal Gear Solid 3: Snake Eater, when EVA/Tatyana threatens the always-nervous Sokolov with a tube of lipstick, who thinks she's trying to kill him. She then turns the lipstick around, puts it on, and walks away. note This is because she also carries a lipstick-shaped gun that's often used by the KGB, which, incidentally, is called the Kiss of Death.
Karst's "Heat Kiss" attack in Golden Sun: The Lost Age, a powerful debuff in the form of a blown kiss.
EarthBound has an enemy that's actually called the Kiss of Death, which is only a smiling mouth with huge red lips. It has the ability to give the "kiss of death", which poisons the victim. There's a similar enemy called the French Kiss of Death.
In Disgaea 3, Marjoly has the ability known as "Oh, Marjoly" in wich she delivers a long and deadly kiss to her target that for some reason deals massive damage. It's Disgaea, so just roll with it.
In Pandect, all Servant Aces have a body part which is poisonous to anyone who touches it. For one character, it's his lips.
The Kids Next DoorMade-for-TV Movie: a zombified Kuki gives Wally The Virus by kissing him. A virus that, mind you, turns people into "Senior Citizombies" — that's right, zombie old people. Number 362 and the other kids find this as Squicky as the audience does.
Transformers Animated. Blackarachnia usually does a non-deadly version of this — and it's a spidery kiss, not a kiss on the lips: she stabs her victim with the legs that stick up over her shoulders and temporarily drains whatever special power they have. However, as proved by her attack on Prowl and Bumblebee in "Black Friday", she can give a deadly one by adding an extra dose of venom, giving the victim two hours to have the antidote administered before they die. Don't worry, while she never actually hands Optimus the antidote, when he goes to see Prowl and Bee and apologize for being unable to save them, he finds the antidote on the ground by them and muses that there may still be some good left in her.
Played straight in The Powerpuff Girls. The girls kiss their male counterparts, which causes them to explode.
Completely subverted when the boys come Back from the Dead and the girls' kisses only make them bigger and stronger.
An rather depressing example: Some time after being born, a baby suddenly fell ill and, despite weeks of life support, passed away from major organ failure. The cause? A virus contracted from a cold sore... from the baby's father.
And the man who was allergic to nuts who died after being kissed by his girlfriend who'd just eaten some peanut butter.
Anime & Manga
The Chinese Amazon kiss of death delivered by Shampoo in Ranma ½: it's a tribal custom when defeated by an outsider woman to kiss them, which signifies a promise to hunt the recipient down to the ends of the earth and kill them.
Princess Tutu: Rue kisses Mytho as she literally yanks his ability to love out of his chest.
In Prétear episode 11, Takako kisses Mawata after successfully driving her into despair, in order to use her soul as a power source for what turns out to be a huge evil tree and then lock Mawata inside of it.
Yoko of Tengen Toppa Gurren Lagann shares a kiss with two separate characters, Kamina and Kittan, immediately preceding their deaths. To be fair, Kittan kissed her knowing that his next mission was suicide.
In Berserk, it is debatable whether Femto/Griffith doing this to Casca counts; he was just about to brutally rape her, and so a Forceful Kiss is not exactly out of place. However, since Casca had already been marked for death by the demon brand, and did not realise yet that Griffith was the one causing all hell to break loose, the kiss served a similar purpose to this trope by making it clear just how much trouble she was in.
In Mirai Nikki, if you kiss Yukiteru and your name isn't Yuno Gasai, you will be dead by the end of the episode.
Films — Live-Action
A big joke (almost to the point of Running Gag) in the Pirates of the Caribbean sequels is that every guy Elizabeth kisses dies. Jack in Dead Man's Chest, Norrington, Sao Feng, and Will in At World's End. Even her father (who she probably kissed a few times, considering how big of a Daddy's Girl she is) dies. Lampshaded in the third movie by Jack, who tells her that "Once was quite enough" when she runs up to him to embrace him.
Michael Corleone's kiss of death to the person who betrayed him in The Godfather Part II is one of the most iconic examples of the symbolic version ever. "You broke my heart. You broke my heart."
Blade Runner. Roy Batty kisses Eldon Tyrell just before squashing Tyrell's eyeballs into their sockets and crushing his skull, killing him.
Just barely averted in American Gangster. When he sees one of his brothers in a flashy suit that might draw the attention of the cops, Frank Lucas sits him down to remind him that potentially drawing attention and notice is a bad thing for major drug dealers. When, during that conversation, the brother also lets it slip that he talked about Frank with one of his rival drug lords (and thus, in his naivete, possibly gave information to this other drug lord), Lucas, who has dealt extensively with the Mafia, gives his brother an enormous kiss and says "You know, if you weren't my brother, I'd have to kill you." They both laugh. Much later in the film, when the brother screws up again, however, Frank beats him viciously for it. And it's all the scarier for coming out of nowhere and with no warning.
Black Widow (1987). The kiss Catherine Petersen (murderess) gives to Alex Barnes (Justice Department investigator). Aside from providing some Les Yay, it also shows that Catherine intends to mess Alex over by framing her for Paul's death.
Averted in the theatrical version of Marvel's Daredevil and done in the Director's Cut. After killing Elektra's father, unintentionally framing her boyfriend, beating her while hitting on her, mockingly treating her revenge like a date, and instantly developing an attraction to her, Bullseye cuts her neck and, intending to use her own sai against her, tries to give Elektra her last kiss. In the Director's Cut, he manages to give her the kiss while she is gutted in the air.
¡Three Amigos!. Just before Ned's duel with The German, Jefe approaches him and kisses him on both cheeks, because he's sure the German will kill him.
Sort of in The House of the Spirits, when Esteban is moving Rosa's body to another tomb and opens up the coffin to have one last look at her. She is completely preserved until he kisses her, after which she degrades very rapidly (keep in mind this is occurring years after she died).
In Holes, a schoolteacher named Kate Barlow angrily refused the local sheriff's offer to save her black lover from being lynched if he kissed her. When she failed to save her lover herself, however, she went back and kissed the sheriff in his sleep, then killed him. After that she left town and became the infamous bandit "Kissin' Kate Barlow," who robbed many (including the protagonist's ancestor) but would only kiss the ones she killed.
In the Tomb Raider novel The Man of Bronze, Lara Croft mentions that she once killed a man while kissing him.
The Godfather's Kiss of Death is also parodied in The Executioner series by Don Pendleton: "Nick told me to kiss you first — I told him you were too damn ugly."
Oz. When Chucky Pancamo kisses Peter Schibetta in a prison corridor, the latter realises instantly what it means and starts shouting "No! No!" Chucky kills him seconds later.
One of the most poignant moments in Xena: Warrior Princess is when she has to kill her undead lover Marcus (long story). She stabs him with his sword, and then passionately kisses him as he dies in her arms.
In Supernatural, when a person sells their soul to a demon, they seal it with a kiss, and then they die ten years later. Note that this applies to all demons — Crowley has made himself quite the master of Ho Yay and Foe Yay due to his insistance on following this particular rule.
On That '70s Show, Kelso is breaking off his cheating relationship with Laurie. Laurie sees Jackie, Kelso's cuckolded girlfriend, over Kelso's shoulder and asks for "one last kiss", thus ensuring that Jackie will see them kissing and break up with Kelso. The episode is actually titled "Kiss of Death."
An episode of The Dukes of Hazzard dealt with a group of mafiosos who were having a meeting in the Hazzard County Jail (long story). Bo and Luke got caught snooping around and were brought before the mob boss, who kissed both of them. Luke put it together that he just gave them "the kiss of death".
The Godfather's kiss of death gets parodied with the mobsters. "The kiss of death. That can't be good."
Parodied again during Homer's stint as Mayor Quimby's bodyguard. Fat Tony tells Homer to give Quimby this and he obliges. When Quimby tells him, "You moron, that's the kiss of death!" Homer worries that he did it wrong and goes in for another.
As a non-mafia related example, in one episode, the oldest man in Springfield dies after a model kisses him for winning an award for it After Mr. Burns is called to take the award instead, he avoids the model, calling the trope by name for his reasoning.
"I know Big Vinnie said he was giving me the kiss of death, but I still think he was gay." "Did he use his tongue?" "...A little."
There are instances when an individual tempts fate, such as declaring failure impossible in a sporting event, that is jokingly referred to as the "Kiss of Death", especially if said person is notorious for bad judgement.