"When you're famous, you become the object of people's projections and it doesn't have a lot to do with you," she chuckles. "I mean, sometimes people think certain things that are, in fact, true; sometimes they're not. What am I gonna do? Go on every talk show and straighten everybody out about who I really am and what our relationship is really about and who tamed who?"
Not that it's a bad way to be perceived - "If I were maligned, maybe it would be harder, but people are nice" - it's just that Bening could not be further removed from a vamp if she tried. Her voice may have that Kathleen Turner-ish husk to it, but her elfin charm is far more that of Sydney Wade, the humble do-gooder she played in The American President - the one who had an illicit liaison with the Chief Executive before such things became fashionable.
Having kids means Bening doesn't work nearly as much as she might. Turning 40 this year has also put her at that "difficult" age when Hollywood consigns its leading ladies to the scrapheap. In which case, her new film, The Siege, in which she is surly and unscrubbed as a CIA agent (opposite Denzel Washington's FBI chief), is a bold venture. "It's not a romantic part, it's not a mother, it's not a sister, it's not a daughter," she says. "It's a woman who is flawed and has secrets and who's made bad choices and with all these complications. That was unusual."
The Siege is certainly unusual. Coming from Ed Zwick, creator of thirtysomething and director of thoughtful military epics such as Glory and Courage Under Fire, this film also has a political slant - what happens when martial law is declared in the Big Apple after a terrorist bombing spree. Being Hollywood, the terrorists are Arab extremists, though the film attempts to raise questions about inherent prejudice against Arabs and Muslims (who are not necessarily one and the same). Like most Hollywood big- guns, Bening is a Democratic fundraiser, but she's refreshingly cynical, especially when it comes to US foreign policy. "It's just so touchy to talk about any of this in the USA. It's almost impermissible."
When trailers for the film appeared in the US, juxtaposing images of prayers at mosques with New York City buses blowing up, Arab groups were not best pleased. "That's a legitimate complaint," admits Bening. "That's marketing. That's scary when you really think about it. Is that what sells a movie? The movie's not anti-Arab. I wouldn't have done it if it was. Listen, it's such a terribly, terribly serious subject. I don't mean to make light of it, but political correctness is deadly. The movie, I hope, makes people think more carefully about singling out an ethnic group."
By the time the film opened in the US, noble intentions undone with the sight of General Bruce Willis gleefully duffing up the terrorists, Arab groups began to picket cinemas. The same questions will surely be raised here.
"Do Islamic extremists exist in the world? Yes. Is it fair to put them in the movies? Yes. Is it good to generalise? No," insists Bening. "There is a lot of anti-Arab sentiment in this country. It's almost still politically acceptable in a way that it isn't in other groups. I hope the movie talks about that."
It's all a long way from Kansas, where Bening was born, or San Diego, where she grew up. After starting out as a dancer, she went to theatre school in San Francisco, evolving into a stage actress who supplemented theatre work with TV work, before ending up in the John Candy/ Dan Aykroyd film The Great Outdoors. Next was Valmont, and though Milos Forman's film fared worse than Stephen Frears' rival Dangerous Liaisons, for which she had also auditioned, Frears kept her in mind for The Grifters, which garnered her a Best Supporting Actress Oscar nomination. Then came her fateful meeting with Beatty.
Casting around for a lesser-known actress for the flashy gangster epic, Bugsy, Bening was courted by Beatty, in both senses of the word. Despite keeping their affair quiet, however, Bening soon announced that she was pregnant and the pair got married in time for the 1992 Oscars which didn't, as predicted, yield a clutch of awards for her husband. Still, they were feted as Hollywood royalty, Tinseltown marvelling at how the ageing Lothario, who had dated most of his leading ladies, and a fair few more besides - Leslie Caron, Joan Collins, Natalie Wood, Julie Christie, Britt Ekland, Diane Keaton and Madonna - had been brought to heel.
Their next movie was the cloying Love Affair, which flopped badly, putting a significant dent in Beatty's viability as a leading man, although Bening bounced back with The American President. Pregnancies have cost Bening the Catwoman part in Batman Forever, Demi Moore's role in Disclosure and a role in What Dreams May Come.
The couple's children - Isabel (11 months), Ben (three) and Kathlyn (five) - have not completely dominated proceedings, though. Next comes American Beauty with Kevin Spacey, a version of Hedda Gabler on stage, and Neil Jordan's Blue Vision, soon to be released.
"I'm lucky, because I get to do other things. I'm an actress. If I was not able to have something separate from my husband and my children, I would be one of those women with pistols to their heads, or I would be in an asylum, or I would be having a nervous breakdown, or I would be an alcoholic, or I would be depressed."
Fortunately, she has a big fan. "Yeah, Warren's very proud of me," she says. "He thinks I'm the best actress."
`The Siege' is released on 8 Jan