Monogamy's all well and good for real life, but it doesn't always work so well for cinema – which thrives on dramas and scandals to hook us in. With US indie director Stacie Passon's hot debut Sundance hit Concussion - about a woman in a committed relationship who secretly starts working as a prostitute for other females after getting whacked in the head by a baseball (as you do) – out this week, here are some of film's other most eye-raising cheating scenarios.
PULP FICTION (1994)
"Look, foot massages don't mean shit," Jules insists to Vincent as the two gangsters debate how understandable it was that kingpin Marsellus Wallace had a guy thrown four storeys off a balcony for massaging his wife Mia's feet. Quentin Tarantino's pop-pastiche crime classic makes clear that even in the grey-area of small gestures, you better know who you're dealing with.
LOST IN TRANSLATION (2003)
Bill Murray's a safe bet, especially when all he's up for is Japanese karaoke. Unconsummated spark is the sweet undertow of Sofia Coppola's indie hit. ScarJo plays a college grad who is married to a photographer with a penchant for flirting with shallow celebs and over-using hair products. She strikes up a rare connection at a Tokyo hotel bar with an ageing actor (Murray), in town to shoot a whiskey ad, amid both of their disenchantment with marriage's realities.
HUSBANDS AND WIVES (1992)
Neurotic Sally (Judy Davis) is distracted thinking about which of her friends are like hedgehogs and which are like foxes to the point of frigidity in bed with the suave Irishman she's hooked up with in this Woody Allen classic. Meanwhile, her husband gets a break from hyper-intellectualising by dating Sally's polar opposite, a bouncy aerobics trainer who's into astrology. The grass is always greener in a mid-life identity crisis – prompting mis-steps that can be ripe comic fodder.
It's risky indeed to chase illicit desires in a baroquely violent, lavish world of spectacle at the hands of extremists Peter Greenaway and Jean-Paul Gaultier. A quiet bookseller regular (Alan Howard) to a high-class French restaurant denies caution when he plunges into a salacious affair with the wife of an English gangster (Helen Mirren). It might be better to burn out, et cetera - though in this case reading doesn't pay.
ROSEMARY'S BABY (1968)
Being under the sway of meddlesome, occultist neighbours might make you less culpable - but if you've been knocked up by Satan himself, your significant other will still probably be quite taken aback, as Roman Polanski's black-witted and absurdist '60s horror starring Mia Farrow and John Cassavetes as a newly expecting New York couple living in an antiquated apartment block shows.
TUESDAY, AFTER CHRISTMAS (2010)
Finding your lover and his wife unexpectedly in the same room as you during a dental procedure is also quite close to Hell itself, this excellent, even-handed and excruciatingly realistic Romanian New Wave depiction of a marriage breakdown, directed by Radu Muntean, suggests.
FATAL ATTRACTION (1987)
Roving-eyed partners were crossing their legs after this blatant '80s Hollywood morality tale starring Glenn Close and Michael Douglas, which made "bunny boiler" common slang for an obsessive lunatic. It warned cosy family units that smouldering business women with minimalist apartments are to be feared – or at least kept away from your pets.
THE GRADUATE (1967)
In this Mike Nichols classic Mrs Robinson, the glamorous lush who also happens to be the wife of his father's law partner, seduces naive 21-year-old college grad Benjamin, played by Dustin Hoffman – who as the affair runs its course falls for her daughter Elaine. It's a bygone era's male fantasy in which chain-smoking MILFs are ever-willing while wide-eyed nice girls wait at the altar (yeah okay).
Daniel Day-Lewis plays a philandering brain surgeon in Communist Czechoslovakia (every girl's dream?) in this US adaptation of Milan Kundera's literary masterpiece. He's in a love triangle with a carefree artist and the small-town waitress that turns up with a suitcase to move in after he sleeps with her. The arrival of Soviet tanks further complicates their lives.
IN MOOD FOR LOVE (2000)
Who needs actual sex, when repressed desire looks like this? Drenched with the melancholy of rainy streets and its iconic soundtracked, this stylised and dreamlike Hong Kong classic from Wong Kar-wai sees two neighbours (Tony Leung and Maggie Cheung) fall for each other when they realise their respective spouses are having an affair, amid smoke swirls and lamplit cheongsams in alleys.