Freddie: Oh, I'm scared of them all right.
Ada: But you love me more than you fear them, right?
Who is that? She's perfect. She's a vision. She's like no one you've ever seen. You've got to get to know her, to learn everything about her.
Many a tale has been told about a poor schmuck who fell in love with a beautiful woman, only to find out she likes someone very dangerous. Usually, the dumb cluck will persist in trying to win her heart and "take her away from all this". Depending on where the story lies on the Sliding Scale of Idealism vs. Cynicism, our hero may get the girl in the end and get away clean, or one or both of them may end up very, very dead. Or he may do the sensible thing and get out while the getting's good. But then there wouldn't be much of a story, would there?
Sometimes both of the guys in this rather deadly Love Triangle are crooks, but the one with the relationship is someone higher up on the food chain, whether by being higher up in the criminal hierarchy (such as The Don in a mafia story) or by being vastly more dangerous than the other.
Compare Mafia Princess.
- A oneshot character in the Black Jack manga does this by accident, he's fallen in love with Pinoko's voice, and a coincidence makes him think the gangster's girlfriend is the one with angelic vocal cords. She isn't, and the would-be suitor makes a quick getaway.
- A story in Petshop of Horrors: Tokyo has a small-time yakuza member fall in love with his boss's girlfriend, who he knew in high school. When the boss tries to frame the member for a crime, the girlfriend agrees to run away with the guy. It ends not so great. The guy falls into the ocean and seemingly drowns so that the girl can escape. The girl is later seen telling a police officer the story, implying that she made it. It later turns out that the yakuza member was turned into a dog and taken in by one of D's purebreds.
- Tarot Cafe has a Romeo and Juliet love story between the daughter of a mob boss and the son of a rival boss. Both know full well what will happen, but choose to elope. The daughter's magic pet cat is also in love with her, but no one actually knows about it. The cat later dies so the daughter and her boyfriend can escape.
- This is what set up the tragic Love Triangle between Spike, Vicious and Julia from Cowboy Bebop. Especially tragic because Spike (who was a Red Dragon member himself) and Vicious used to be the best of friends before this.
- Ian from A Cruel God Reigns has a fling with a gangster's wife, although it turns out that he is possibly only a soldier.
- Bertram Potts for Sugarpuss in Ball of Fire.
- Mad Dog And Glory has a crime scene photographer and the bartender at the bar of a mob guy whose life he saved. Mad Dog learns that Glory is trying to pay off a personal debt to Milo, the aforementioned mob dude, and after coming up short of the money needed, he has to fight Milo, after which they make peace and Milo lets Glory go.
- Bound (1996) is a Gender Flip version, or half of one. A lesbian ex-con falls in love with a mafioso's girl, and the girl reciprocates. Then they hatch a scheme to get rid off him, which ends up backfiring on them when he proves to be far more resourceful than either of them anticipated.
- An in-universe one in Singin' in the Rain; in the Film Within a Film The Dancing Cavaliers, Gene Kelly's character has a Dream Sequence where he imagines himself falling for Cyd Charisse, but ultimately losing her to her mobster boyfriend.
- Played with in Pulp Fiction; Vincent senses the rising tension between him and Mia and explicitly warns himself to avoid this trope. Not in the least because there's a rumor circulating that his boss Wallace crippled one of his other employees for screwing around with his wife, although Mia herself denies this was the reason and thinks that incident was strictly business-related.
- Stanley Ipkiss falls in love with Tina, the girlfriend of Dorian the gangster in The Mask. It results in a big showdown between the two of them, once Ipkiss gets the mask back. And it's Tina who decides she likes Stanley enough to leave Dorian, rather than Stanley trying to take Tina away.
- The Cook, the Thief, His Wife and Her Lover is a good example of the "doesn't turn out well for the guy" version.
- Little Shop of Horrors: Seymour is in love with Audrey, who is the abused girlfriend of a sadistic dentist.
- In Dick Tracy, 88 Keys feels this way about Breathless Mahoney, whom Big Boy Caprice appropriated from one of his rivals after sending said rival to his death.
- The Girl Can't Help It ends up being this. Fortunately, the gangster realizes he was just pushing his girl to help him get back his Glory Days. Once he finds his own way, he lets her go.
- The movie The Marrying Man starts with the protagonist sleeping with a woman who turns out to be the girlfriend of the notorious gangster "Bugsy" Siegel. Uncharacteristically the gangster is a good sport about this and rather than having the couple killed, he has them marry each other.
- In the movie Wild Side Alex falls for Virginia who is involved with international smuggler Bruno. A Les Yay version of the trope (Alex is a girl).
- This sets up the final tragedy of El Mariachi. Here, the title character falls in love with Domino, the girlfriend of druglord Moco. The Mariachi survives, but Domino isn't so lucky.
- Elvira, drug lord Frank Lopez's girlfriend in Scarface (1983). She eventually marries Tony, but the lifestyle of a druglord isn't very conducive to a happy relationship, especially since Tony disregarded her advice about not getting high on his own supply, leading to Tony becoming increasingly unstable and costing him his relationship with her.
- In Lost Highway, Pete gets in deep with Alice, the gangster boss' girl.
- James Bond:
- Expectedly, there have been quite a few Bond Girls who were the girlfriend/mistress/wife of the Big Bad: Domino Derval from Thunderball, Solitaire from Live and Let Die (though she had a platonic relationship with the Big Bad, to preserve her psychic abilities), Andrea Anders from The Man with the Golden Gun, Kara Milovy from The Living Daylights, Lupe Lamora from Licence to Kill, Paris Carver from Tomorrow Never Dies (who also happened to be one of Bond's former lovers), and Severine from Skyfall. Additionally, in Casino Royale (2006), Bond beds Solange Dimitrios, wife of The Dragon Alex Dimitrios. As befitting the darker aspects of this trope, fully half of these women do not survive their respective films.
- On Her Majesty's Secret Service provides a subversion - the Bond Girl is the daughter of a gangster, but the gangster in question is Bond's ally. Unfortunately, she fares no better than the unlucky Bond Girls above.
- Averted in Spectre, where Lucia Sciarra is the widow of this type of man, thanks to Bond killing her husband, but in no less danger from his vengeful associates. She manages to be one of those who survive. There's also a variant in the movie with Madeleine Swann, Mr. White's daughter, who becomes Bond's ally and love interest as he goes after SPECTRE.
- Emma, Harry and Paul in Born Yesterday.
- In The Whole Nine Yards, Nicolas "Oz" Oseransky falls for Cynthia Tudeski the estranged wife of Jimmy "The Tulip" Tudeski. Fortunately for Oz, Jimmy falls for fellow assassin Jill and moves on with his life.
- In The Fast and the Furious: Tokyo Drift, Sean manages this twice - first in the prologue with the school bully's girl. It doesn't end well, and he ends up on the next plane to Tokyo. There, he falls for Neela - her boyfriend, DK, is a Yakuza associate on top of his standing in the drifting community.
- The Hitman: Garret, an undercover cop working as a hitman for the mafia, has a fling with a mob accountant who also happens to be the mistress of the boss he's working for. He finds out. She eventually ends up with a bullet to the back of her head, Garret ends up getting sold out to the competition.
- Played with in Solo. Han Solo discovers his old girlfriend Qi'ra, whom he still loves, is now the right-hand woman of powerful gangster Dryden Vos, with both of them making it pretty clear Vos won't let her go without a fight. It's not made explicit that there's a romantic/sexual relationship between them, though some of Vos' behavior towards Qi'ra indicates he doesn't just think of her as his employee. Han being Han, he ignores everyone's warnings to pursue Qi'ra anyway, offering to take her away from Crimson Dawn to begin a new life. It doesn't end well.
- In The Cotton Club Dixie Dwyer is a singer who is in love with Vera Ciciero- who happens to Dutch Scultz's girlfriend. Dutch is not pleased.
- Leads to the final fate of the main character in The Brief Wondrous Life of Oscar Wao.
- The Stephen King story "The Ledge" from Night Shift deals with a man who falls in love with a gangster's wife and is forced to walk a ledge all the way around an apartment building. It's very high up and the ledge is six inches wide. If he wins, he gets the girl, n.q.a. If he loses, he falls to his death. This guy being a criminal, of course, there's a rather nasty loophole in the deal.
- The Sidney Sheldon novel A Stranger In The Mirror twists this around. The protagonist, a famous comedian, beds a gangster's mistress, but he has no interest in her beyond a one-night stand. Regardless, he's still terrified when the gangster and his cronies show up on his doorstep, only to have the gangster pull an I Want My Beloved to Be Happy and demand that he marry the girl, as she's head over heels in love with him. Given the kind of man he is, he threatens him anyway, pairing this with an If You Ever Do Anything to Hurt Her....
- The deuteragonist of The Valley of Fear deals with this by gaining the favor of the gang himself. It does get his rival to back off, but needless to say, the love interest is not thrilled.
- A key element in the Iain Banks story "Dead Air". The relationship and the potential consequences of that guy finding out drive much of the plot.
- Furio with Carmela in The Sopranos. Subverted in that Furio is a gangster too, but Tony is the boss.
- In the second season of Boardwalk Empire, Owen, an IRA enforcer who works for Nucky, starts pursuing and eventually sleeps with Nucky's mistress Margaret. Since the show has some of the same creators as The Sopranos, comparisons between Owen and Furio happened almost immediately.
- In the Star Trek: The Next Generation episode "The Royale", Riker, Data and Worf are stuck in a virtual reality simulation of a poorly written book where the bellhop at the eponymous hotel/casino is in love with a gangster's moll. The bellhop has a gun with which to "deal" with the gangster, but the gangster kills him instead.
You should have listened to me, kid. No woman's worth dying for. Killing for, not dying for.
- A modern retelling of The Canterbury Tales on the BBC featured this trope in an adaptation of "The Sea Captain's Tale". In the original, the cuckolded husband is a ruthless banker/usurer with a manipulative, extravagant wife. In the adaptation, the usurer is The Don of a South-Asian community and is a money lender and "importer/exporter". In both versions, the seducer borrows money from the husband on her behalf. In the modern version, the guy is more innocent, and the husband is a Crazy Jealous Guy, so things don't go well.
- Castle had an episode "The Blue Butterfly" involving the 50-year-old diary of a gritty private eye, a scuzzy crime boss, a gorgeous gun moll, and a diamond-encrusted butterfly. That one actually turned out very nicely.
- In Flashpoint, an undercover agent becomes involved with the drug leader's girlfriend and his actions to protect her while bringing down the drug gang only led to trouble for him, her and Team One.
- In TwinPeaks Juvenile delinquent Bobby Briggs is having an affair with Shelly Johnson, the wife of the more seasoned criminal Leo Johnson
- Also Sheriff Truman and Josie Packard.
- In "El Paso" by Marty Robbins, both the male love interests end up dead.
One night a wild young cowboy came in. Wild as the West Texas wind.Dashing and daring, a drink he was sharing with wicked Feleena, the girl that I love.
- The song "Solomon Jones" by Aceyalone & RJD 2 ends in a shootout between "Big Bad Solomon Jones" and a mysterious man who had wandered into his bar, all over "the lady known as Simone".
Then all of a sudden the music changed, and everyone just held their pulseBut it felt like your life had been robbed from you, and everything that you held closeThat someone had stolen the woman you loved, and that her love was a devil's lieThat your heart was gone, and the best thing that you could do was crawl away and dieIt's the painful cry of a man's despair, deep down in his bones"I guess misery enjoys company", said big bad Solomon Jones
- Inverted with "Copacabana" by Barry Manilow. A gangster sexually harasses the showgirl the bartender's committed to. It gets the bartender killed, and the showgirl ends up as a broken alcoholic.
- Also Inverted with Jim Croce's "Bad, Bad Leroy Brown." Leroy is used to having what he wants, sexual conquests included. He makes the mistake of trying to bed "the wife of a jealous man" and ends up having his ass kicked in full view of the neighborhood.
- "Hide Your Heart", by Bonnie Tyler (though written in part by KISS member Paul Stanley, the band did not do a version until after Tyler).
- Downplayed and Played for Laughs in Jay and the Americans "Come a Little Bit Closer." The narrator is in a bar and the girlfriend of "Bad Man Jose" flirts with him. Attracted, he has a dance and kisses her...but then Jose shows up and he jumps out the window to avoid Jose's wrath. The girlfriend, without skipping a beat, goes and uses the same come-on lines on Jose she was using on him.
- Luann. Luann's brother Brad fell in love with his next-door neighbor Toni Daytona. Unfortunately, she turned out to have an emotionally abusive and dishonest boyfriend named Dirk, who was extremely muscular and could have broken Brad in half without trying.
- This was the plot of the 1921 musical Good Morning Dearie, where it led to the first act ending with a fight scene.
- The Donbot's wife on Futurama's episode "Into the Wild Green Yonder" cheats on him with Bender. They're... less than subtle about their relationship.
- Henchmen 21 has a crush on Dr. Mrs. The Monarch on The Venture Bros.. She's fairly dangerous herself, but her husband (guess who) is fairly cavalier about killing his henchmen if they so much as take him by surprise. He eventually quits his job when he's no longer able to handle working with her and the other mounting psychological issues the job's causing him.