You are getting increasingly frustrated. Your Love Interest is ignoring your affections for him/her, even though you're making it oh so blatantly obvious. And you love him/her so much, so much that you can't stand it, that you wish he/she would stop ignoring you, and stop being so oblivious to your love for him/her. What do you gotta do?
Why, grab him/her, pull them close to you and plant a big wet one right on those lips that you've been dying to kiss for so long! And of course, you may not think about what possible consequences that your actions could bring you, since you are just too damn excited at being able to be so close to your love.
Note: engaging in this trope means that you may be a bit overly confident in your attempts to "woo" someone, you may have no idea how to actually do the whole romance thing, or you just couldn't help yourself, and you simply had to get your feelings across somehow.
Sometimes overlaps with "Shut Up" Kiss and Tsundere. It may also happen to a person who is the victim in a I Have You Now, My Pretty moment. May or may not hint at an Attempted Rape.
Near the beginning of JoJo's Bizarre Adventure, Dio Brando steals a kiss from Jonathon Joestar's girlfriend as part of his grand plan to humiliate him.
Shugo Chara!, where famous Idol Singer Utau Hoshina forcefully kisses the mysterious cat-boy Ikuto Tsukuyomi, much to the shock and horror of Amu, Kukai and their Charas (to quote Ran, "It's an adult's world!"). And it becomes Squick once you realize how they are related: she's his sister...
And Ikuto himself is so displeased that he slaps her away.
Romeo gives Juliet one in Romeo X Juliet. Complete with romantic bridge setting and fireworks.
Louise plants a kiss on Saito for their Master-Familiar contract in the first episode of Zero No Tsukaima. She also does this again at the end of the first season.
It's also used by Agnes to Louise and Henrietta to Saito, as part of a Fake-Out Make-Out ploy.
To keep Riku quiet so he won't be discovered Dark surprises her with a forceful kiss in the first episode of D.N.Angel.
Not quite forceful, but Akito still manages to steal an unexpected kiss from Sana in Kodomo No Omocha. Her reaction was...well...animated.
Girls Bravo: The Fukuyama siblings are quite fond of using this trope when it comes to their objects of affection. Kosame does this to Kirie once too.
Since a kiss on Negi is required for a Pactio and Harunareally wanted the Artifact that comes with the Pactio, she does this on Negi. Twice.
Evangeline once forced a kiss on Negi too, "as a fee for her advice. Asking favors from an evil mage always requires payment."
There is also the part with the multiple fake Negi: One of them tries to forcefully kiss Yue, and explodes after she repels him. Said fake, named "Nugi", makes a reappearance as a golem that Haruna made for the girls to practice their Pactio kisses on. Naturally, it doesn't go as planned, and Akira suffers for it.
Sinbad has grabbed Kaitou Jeanne and kissed her at least twice. The first time, Jeanne was too shocked to do anything, but the second time she immediately shoved him away (then wondered where he went; maybe a rooftop wasn't the best place for that).
In Strawberry Panic Yaya does this to Hikari at the end of episode 13. In the following episode when we see the scene again Hikari shoves Yaya to the floor when Yaya starts to grope her. An understandable reaction seeing as how Kaname had just tried to rape her before that.
In Junsui Adolescence, Kiiko forces a kiss on her friend Abi believing that that is as far as she will ever get. Then Abi forces a kiss on Kiiko when the girl tries to run off.
In Rave Master, Lucia does this to Elie, causing her to cry and enraging Haru to the point of wanting to kill him.
In Infinite Stratos, Laura Bodewig forces her tongue down Ichika's throat and declares that they are going to be married.
In Taboo Tattoo, the Big Bad princess does this to the heavily exhausted and defenseless main character in chapter 9.
Märchen Awakens Romance: The Phantom attempted this on Alviss at least twice. The first time was during Gintas nightmare and the second was when Alviss got captured and he had him in his grasp. Fortunately, Alviss was smart enough to pull away fast enough the second option. The first one, Nanashi saved him. Then again, this was Ginta's dream so...
Ai No Kusabi: Iason's favorite method to calm Riki down when the Pet Ring doesn't. On at least one occasion it's just to shut Riki up.
In Pandora Hearts chapter 3 Alice does this to Oz. This case is a little different because it's not because she likes him - she reveals later that she doesn't even understand the implications of a kiss; she was only doing it to get her blood into him... somehow.
In episode 7 of Mirage Of Blaze Naoe tries to do this to Kagetora but Kagetora shoves him away.
Koharu No Hibi: Koharu does this to Akira in chapter 12. In chapter 16 Koharu does this to Mika because she wanted to be the one to be Akira's first kiss and Mika kissed him first so she was taking his kiss back.
Lio Shirazumi from Kara no Kyoukai forcefully kisses Mikiya in order to transfer a drug/poison into his body that will kill him.
Kyo Koi O Hajimemasu: Kyota grabs Tsubaki's hair in order to kiss her as payback for cutting his hair and as a declaration that she's his new target.
In Honoo No Alpen Rose, Mathilda gives one to Lundi much to his shock and disgust. For worse, Lundi's girlfriend Jeudi sees them from a distance — and this, coupled with a very recent attempt on the poor girl's life, causes Jeudi an Heroic BSOD.
Luke Skywalker is subjected to a number of these in Marvel Star Wars, probably because he's never really willing to make the first move. A lot of them come from a woman named Dani who he's only interested in as a friend; eventually he stops reacting with shock and dismay and just casually dodges.
Happens in the original Teenage Mutant Ninja Turtles series in the story entitled Sky Highway. In an alternate dimension, Raphael lands in the passenger side of Hildagaard Rail's car. She was a blonde german woman who had long legs and wore a dress that exposed her ample cleavage. However, spending time in this dimension mutated her giving Hildagaard gigantic lips that went practically from forehead to chin and ear to ear. When Raphael tried to leave her vehicle she grabbed him by the streams of his bandana, pulled him close and said "Shut up and kiss me, you dumkoff!" Her long passionate forced smooch left a lipstick mark that covered Raphael's entire beak and even got on his teeth. When Raphael managed to get away from her Hidagaard Rail called out, "Unt I was sure you would turn into a prince! Auf Wiedershen loverboy!"
In the prison AU "Murderer's Row", O'Malley has quite a few of these with his poor little Doc. A side one-shot shows that it goes far beyond kissing. O'Malley also does this to Donut once (mistaking him for Doc) but that results in a chunk of his tongue being bitten off.
In the Kalash93 story, Relax, the protagonist is suddenly grabbed and snogged rather forcefully by his lover during some post-coital cuddling.
DC Nation: Starfire's fantastic restraint was demonstrated aptly when Cyborg snapped her out of Unstoppable Rage brought on by a Red Lantern Ring. Yup. Middle of a battlefield during Blackest Night, and Kory stops to plant on on her teammate - right before flying back in to kick some more Black Lantern butt.
In TSA The Amazing Spider Man Tabitha does this to Johnny Storm and then she reveals she has a list of heroes that she is going to kiss if she ever meets them in person number 5 is Johnny, number 4 is Mr. Fantastic, number 3 is Warbird, number 2 is Thor and numero uno is Spider-Man.
Films — Animated
Subverted in Ratatouille: Linguini does this to Collette but only because Remy prods him into it. A little clip from a French film Linguini is watching earlier shows a man inflicting this on a woman with passionate results — apparently this is just the way things are done in Paris.
In the second Shrek movie Prince Charming does this to Fiona at the ball.
Jasmine to Jafar in Aladdin to distract him from discovering Aladdin.
Films — Live-Action
In Pirates Of The Caribbean: At World's End, Elizabeth is taken to Captain Sao Feng's chambers where they talk for a bit before he plants a violent kiss on her. (An explosion soon interrupts him.)
In The Princess Diaries Josh does this to Mia in front of some photographers after they chant for him to do so, publicly humiliating her.
The first film of The Mummy Trilogy. Imhotep plants one on Evy in her sleep. It doesn't help that when she awakens, his mouth has become decayed. Later, there is a subversion where Evy FORCES HERSELF to kiss Imhotep to prevent him from killing her rescuers.
Rick also plants one on Evy when she and Jonathan visit him in prison early in the film.
In the 1981 horror film Fear No Evil, the teenage Antichrist is being taunted in the shower by the Jerk Jock as being gay, but eventually he turns the tables on his tormentor by attacking him with a very long and forceful kiss on the mouth.
Auntie Suga does this to Craig in Next Friday since she had a really big crush on him despite the fact that she is sleeping with his uncle. When Suga motions for Craig to give her a kiss on the cheek goodbye she grabs him and forceably rams her tongue down his throat.
In Some Like It Hot, Sugar Kane is performing a sad song after getting dumped by her latest beau, Junior. At that moment, Joe (disguised as Josephine) rushes by, grabs her and kisses her right in front of the audience.
In Heathers, done to Veronica a lot by J.D., even though most of those could cross over into the unwanted "Shut Up" Kiss.
Bruce Almighty, Susan Ortega, who had been showing interest in Bruce, finally forces a big one on Bruce's lips after hearing that his and Grace's relationship had been struggling. It backfires after Bruce sees Grace watching the two from afar.
In Donovan's Reef, John Wayne (Donovan) kisses Elizabeth Allen (Amelia Dedham). She resists ... at first.
Given Ambrosio believes he is committing rape out of love in The Monk, this isn't surprising. Pf course, he only freaks out Antonia.
In the Wheel of Time, Mat saves an Aes Sedai from Seanchan attention the only way he knows... by snogging in a corner. Hiding in plain sight, if you will. She's scared out of her mind at the time, and while she goes along with the kiss for the sake of camouflage, afterwards she collapses. Despite being a renown womanizer in-universe, he has a policy of not getting mixed up with Aes Sedai, even the cute ones, making this one of the most platonic examples on this list.
In Venetia Oswald Denny attempts this as the result of weeks of jealousy, "calf-love", and teenaged sulking. He doesn't know how to make the kiss actually happen, though, and he gets pulled off before he gets very far.
Actually, Georgette Heyer is very fond of this trope in general. April Lady, The Convenient Marriage, Sylvester, Lady of Quality, and The Corinthian all have successful Forceful Kisses.
Live Action TV
Quite often in Smallville, and all of the following are on Clark. Don't ask how some human girls are able to do this to the Man of Steel.
Chloe in Hug
Chloe again in Rush.
Chloe again in Magnetic.
Chloe again in Devoted. Yes, that is once per season.
Lois in Crimson.
Maxima in Instinct.
Alternate-universe Tess in Luthor.
In Oz, Ryan becomes Dr. Nathan's Stalker with a Crush after she helps him through his battle with breast cancer, and in one instance, forcibly kisses her, among other things.
Keller does this to Beecher twice. Once after knocking him out and handcuffing him to a chair, the other right before killing himself in such a way to make Beecher look guilty.
Claire Howell does this to any guy that captures her predatory interest.
Gordon Brittas (played by Chris Barrie), the eponymous character from the British comedy series The Brittas Empire, daydreams about deputy manager Laura and himself; the fantasy sequence starts with him being entirely oblivious to her desperately trying to tell him how much she loves him. Finally she gets fed up with this and starts kissing him passionately. Just then, Brittas is jolted out of his daydream when the door opens and the real Laura comes in.
Odo and Kira's first kiss in Star Trek: Deep Space Nine — Odo pulls Kira in for a kiss in front of everyone on the Promenada after he "suggests" it and she replies, "Well, why don't you?"
Finally happens in Angel after Fred's spent several episodes trying to hint at her feelings for Wesley, while he's been too distracted and selectively oblivious to notice. After confronting him and trying to explain how she's been trying really hard to get him to notice her, and leaving him speechless in the process, she finally gives up explaining it and just runs across the office to grab and kiss him. Since he'd already been in Unrequited Love with her for the past few seasons, he had no objections.
Monica gives Chandler one of these in Friends. Played with in that she isn't harbouring romantic feelings and just wants sex. (Ironically, it's hinted that Chandler is the one with the crush). The kiss kick-starts their romantic relationship and they fall in love.
How Kate finally gets her point across to Robin in Robin Hood. She's been acting weird, Robin yells: "Why are you so angry with me?" and she grabs him and kisses him.
This is how Gretchen in Heroes makes her crush on Claire known.
Claire also got one from Sylar, which she responded to by stabbing him in the eye.
On The X-Files, Mulder kisses a woman who looks like Scully (but isn't, thanks to a Wizard of Oz dream) right before he jumps off the ship he's marooned on. The woman does not take it lightly, and gives him a sound punch to the face.
This probably also counts as a Now or Never Kiss, since the reason he kisses her is that he isn't sure if the timeline (he's trapped in the past) will return back to normal, and he'll ever see the real Scully again in the present. So he decides to kiss the next best thing, "in case we never meet again".
iLost My Mind picked up on the cliff hanger. Now they're in the middle of a four-episode love arc.
This is how J.D. and Elliot share their first kiss on Scrubs.
In Guiding Light, a (slightly) drunk Olivia kisses Natalia like this. That was their first, and only, on-screen kiss. They lived happily ever after though.
Korean drama Goong had the prince do this to the female protagonist twice. First time, we don't see her reaction, though at the freeze-frame, she looked notably shocked. The second time, she slapped him.
Lana Shields does this to Jack Tripper several times on Three's Company. At times Jack seems to enjoy the kissing while it takes all of his energy to resist her feminine wiles. At one point he had to control his heavy breathing while she approached him. Another time she forcefully made out with him, and his body went numb as if he resigned. Jack was repelled because she was older than he was but once she got her lips on him it was difficult for Jack to get away. Eventually Lana was written off the show because it seemed illogical that Jack wouldn't return her affections.
Cassandra manages to snog the Doctor while she's in Rose's body. He doesn't know that it's her, and is left very stunned.
The Madame de Pompadour pushes the Doctor against a wall and kisses him with very little introduction. He's pleasantly surprised once he finds out who she is.
In a very funny scene from "The Unicorn and the Wasp", the Doctor has been poisoned and is self-administering a "detox" that involves consuming ginger beer, walnuts, anchovies, and some kind of shock. For the shock, Donna plants a big smooch on his lips. It's a shock because they're actually Platonic best friends.
Amy Pond does this to the Doctor halfway through her first season. It's completely unwanted, but she manages to get him up against the TARDIS door and just goes for it. He scrambles away while flailing a lot and reminds her that she has a fiance, and she's human, and he's 907 years old and doesn't like her that way.
The TARDIS very forcefully kisses the Doctor as soon as she's in a proper human body. Then bites him on the ear. He doesn't recognise her, and is extremely confused.
River Song gives the Doctor his first kiss with her simply because she expects that he's already used to it. Due to their Timey Wimey Ball timelines, he's not, and flails aimlessly a bit before eventually returning the sentiment. Her first two kisses with him (from her perspective) were also entirely unwanted on his part: the first one is with poison lipstick and kills him, and the second one is a Heroic Sacrifice on her part and revives him at the cost of all her future regenerations.
In Seinfeld, Kramer surprises Jerry with a forceful kiss in "The Kiss Hello".
Kemal Pamuk does this to Mary on Downton Abbey - followed not long after by his going to her room and demanding sex. (She later acts as if it was consensual, though he'd arranged things so that it would be very awkward and difficult to say no.)
A one-shot female character does this to Magnus near the end of "Monsoon." Magnus happily returns the favor.
Happens at Yuna and Seymour's wedding in Final Fantasy X. It is incredibly squicky for several reasons: How much Yuna doesn't want it, how much Seymour on the other hand does, Tidus' reaction, and the fact that Seymour is dead at the time.
In "Arnold Visits Arnie", Lulu, a lookalike of Lila, attempts to do this to Arnold once. And fails.
But in "Deconstructing Arnold" Curly succeeds after Rhonda, taking Helga's advice, "professes" her love to him in an attempt to repulse his amorous advances:
Rhonda: Okay, Curly, I admit it - I'm your secret admirer. And the truth is, no matter how hard I try and fight it, I'm (reading notes on her hand) really, really wild about you. In fact, I've fallen crazy in love. So whadda you say - how does that make you feel?
Curly: (grabs Rhonda in a passionate embrace and says) Give Daddy some sugar... (and lays a big fat wet one on her)
In Code Lyoko, Aelita does this to Jérémie at the end of "XANA's Kiss". It's more surprising than forceful and ends with Jérémie in a Post-Kiss Catatonia.
Sissi also does this to Ulrich in episode "Ultimatum" — knowing that if she was going to forget about it because of the Return to the Past, Ulrich wouldn't.
This happens to Woody Woodpecker in a Fine Feathered Frenzy. Gorgeous Gal had a sexy voice but was an overweight and elderly crow who fell in love with Woody Woodpecker. When he accidentally ran into her arms Gorgeous tried to kiss him on the lips twice but he turned his head so she got both of his cheeks instead. Later she grabs her 'dream boy' while she is sitting on a couch and puckers her giant red lips getting them ready for action. The smitten senior citizen holds him down and kisses the Woodpecker on the lips twelve times. He eventually breaks free and can be seen smiling for a split second so he may have enjoyed the kissing even if he is mostly turned off by her weight and age. Gorgeous Gal however becomes ecstatic and her lust intensifies. She rushes to kiss him and offers her lips to him a few more times but the Woodpecker flees. Once Gorgeous Gal gets a priest to marry the two and traps Woody Woodpecker in a submarine chances are he doesn't escape the inevitable forced kiss to the bride.