The man sitting in front of me should be awarded an MBE for Services to Older Women. Not that Stephen Vizinczey wrote the global bestseller, In Praise of Older Women - which has sold over seven million copies since it was first published in 1965 - out of charity or condescension. No. He wrote it out of love: a love he still feels viscerally, more than 50 years since the book's publication in Britain.

"I remember a friend, who was a former alcoholic, once saying to me: 'From the moment I had my first sip of gin, I knew that alcohol was for me'," smiles the 83 year-old, from the recesses of a velvet sofa in his Chelsea flat.

"Well, I feel that way about women. From the moment I first hugged a woman at the age of six, and buried my head in a woman's breasts, I knew that that was for me.".

A cultural shift to be praised

Having recently published his first new novel in 16 years - the brilliant time travel adventure, If Only - the Hungarian-born author tells me that the cultural shift we're witnessing today, away from the idolatry of youth and toward an appreciation of older women, is one to be celebrated.

And a celebration - of a very intimate kind - might be one way of describing what Wendi Deng was pictured doing recently with her own 21 year-old Hungarian toyboy on a sun-lounger outside her villa in St Barts.

Over the past month Rupert Murdoch's 48 year-old ex-wife and model Bertold Zahoran have been enjoying so public and intense a romance that it makes Madonna's new relationship with another young model, 25 year-old Aboubakar Soumahoro - pictured snuggling up to the 58 year-old singer on the slopes last week - look positively chaste.

But nothing about these reciprocal enchantments comes as any surprise to Vizinczey, whose admiration for older women hasn't wavered since that first hug all those years ago. In Praise of Older Women tells the amorous recollections of Andr??s Vajda, a young Hungarian philosophy professor who embarked on a string of love affairs with older women, a proposition the author encourages - if not the language used to describe it.

"These terms people use nowadays - the 'toy boys' Helen Fielding writes about and the 'cougars' - these are ridiculous," he laments.

"There's this need to label now - why? Because in the end sex is a complete mystery, and so they try to pin it down with these terms, which are pejorative to women too, aren't they?".

Absolutely, I say. After all there is no such pejorative term for the many men who date or marry younger women. "Yes there is," flings back Vizinczey, astonished: "Old goats."

An old classic re-released

Possibly capitalising on the rash of high-profile intergenerational love stories playing out across magazine covers the world over (Heidi Klum, Demi Moore, Jennifer Aniston and Jennifer Lopez have all been labelled "older women"), Penguin re-released the book as a Modern Classic, five years ago.

Perhaps they needn't have bothered putting a bare-chested woman on the cover: when Vizinczey popped into Hatchards in Piccadilly before Christmas, a shop assistant informed him that the book had sold 400 copies in that branch alone over the past few months.

I wonder whether this is another sign that, even in notoriously ageist industries like fashion, beauty and the media, 'youth terrorism' is on the wane - with some, like photographer Peter Lindbergh, who recently unveiled the latest Pirelli Calendar, featuring the unretouched images of Nicole Kidman, 49, Uma Thurman, 46, and Helen Mirren, 71, actively campaigning against it.

And not a moment too soon. For the past few decades, the idea of 'older women' having any kind of sexuality has become culturally taboo - something that prompts Vizinczey to bury his face in his hands.

"When I wrote In Praise of Older Women I thought the whole world would understand it. Because actually women are sexier than men for so much longer. And I know lots of women who say that sex gets better with age. My wife was a sex fiend until her early seventies!" he whispers of 90 year-old Gloria next door - the older woman and mother of their three children he chose to marry 53 years ago.

"After all, you're more relaxed and less self-conscious as you get older - and you certainly know your body better, so it stands to reason you would be sexier."

What the women who "do things to their faces haven't realised," he says, "is that their brains are their greatest assets. Take Helen Mirren, for example. I remember seeing her in Turgenev's A Month in the Country in the Sixties and she was beautiful then, but she's got more beautiful because she's got brains - and that's the greatest sex appeal in any woman."

The idea that women should be more worried about ageing than men doesn't just sadden but incense Vizinczey.

A history of provocation

Despite it being the tenderest ode to the opposite sex, feminists were appalled by In Praise of Older Women when it was first published, while his second book, An Innocent Millionaire - a blistering attack on avarice and hypocrisy - wasn't for the faint hearted, winning praise from the likes of Graham Greene and Anthony Burgess.

If Only is also not without its provocative themes, set as it is in a defiantly unprettified Britain "where there are Christians who hate Muslims and Muslims who hate Christians."

But it also paints a poignant picture of what a truly happy marriage is - something Vizinczey knows more than a little about.

The story of a software company boss, Jim Taylor, who tries to drown himself after being fired but is rescued by a child from outer space and given a second chance at life, If Only manages to blend disparate themes into a single story in much the same way as In Praise of Older Women.

One of these, I'm amused to see, is the danger of unions between older men and younger women. "It just doesn't work so well the other way around," laughs the writer. "In fact I know many men who were destroyed by marrying younger women."

If he - like his antihero - were given a second chance at life, is there anything he would do differently?

"I would draw up better contracts," he flings back without a moment's thought. Then, looking lovingly over at the wife who has come to sit beside him. "And I would have married her earlier."