The Wife of Bath is the best known of Chaucer's Canterbury Tales characters, presumably because the humour of this particular social lampoon transfers so readily to a modern readership. The ageing, man-eating harridan has long been a comedy staple. We've barely made her acquaintance before she's telling us in her Prologue, "Thanks be to God Who is for aye alive,/Of husbands at church door have I had five."

Hmm. Now, who does that bring to mind? A clue was offered by the Daily Mail's commentary on I'm a Celebrity... Get Me Out of Here! this week, with a headline: "Screaming Leeming. She scared off FIVE husbands. Now Jan Leeming's jungle antics are terrifying millions." The reader was left in no doubt that Leeming stood accused of the heinous crime of lechery at an age where they'd rather see her advertising Stannah stairlifts.

So many media commentators professed themselves outraged by her "inappropriate" flirtations with men "half her age" that I found myself forced - against my will, you understand - to watch highlights. Imagine my disappointment when, instead of being shown clips of Leeming clutching Jason Donovan's goolies while licking Toby Anstis's chest, the worst ITV could come up with was a clip of her saying with unabashed admiration, "Toby, do you work out?" Outrage! Highly attractive woman of 64 admires 35-year-old male's pecs. Which, as we know, is only permissible if you are a young, comely secretary in a Diet Coke ad.

Now let's imagine the reverse scenario: 60-somethings Mick Jagger and Jack Nicholson are in the jungle and they ask 28-year-old Myleene Klass if she goes to the gym (by the way, ITV have been showing repeat footage of buxom Klass in her bikini, which is presumably being lapped up by male pensioners, as well as Nuts-reading lads). Well, that's just natural, innit?

As a society we largely take the view that men of all ages are programmed to appreciate the female form and we should just deal with it. As a teenage barmaid in my parents' pub in Kent, flirtatious banter with ageing males was part of the job description. There was one regular called Alf, an odd-job man in his eighties, who was always trying to plant goodbye kisses on my and my sister's lips. The weekly charade of the Pelling sisters trying to avoid Alf's vice-like grip caused great mirth among the other locals. But I can't recall an occasion when my two brothers had to deal with an over-enthusiastic matron.

Yet it's patently obvious that most women over 50 don't suddenly lose all interest in the manifest charms of strapping young men. If that were true, why did every grey-haired mum in the country fancy Robson Green and Jerome Flynn in the 1990s? Why are women who haven't been to a Bond movie for 20 years flocking to lust at Daniel Craig? Female over-50s form the big growth area in the dating market and a clutch of recent surveys say they're having the best sex of their lives, often with significantly younger men.

Where older women do differ from their male counterparts, however, is that they remain under social pressure to curb any public displays of sexual entitlement or enthusiasm for younger men. The message is that such pairings will only be sanctioned if the tentative first endearments take place off-stage where the general public won't be disgusted. And we prefer to be told it was the young man who pursued the older woman, because this is gallantry, whereas an older female propositioning a youth is plain depravity.

It's usually women who are the fiercest criticsof the ageing vamp because it taps into our deep fears of looking ridiculous. At the age of 38, I already instinctively tone down any sparkle when chatting to men in their teens or twenties, lest they think I am giving them the glad eye. It's hard to shrug off social conditioning that informs us there's no greater humiliation for any female than to look like a sexually predatory old woman.

Just look at the barrage of critiques of poor Ms Leeming posted on I'm a Celebrity blogs: "The lasting image we are going to be left with after this is that of a sad, embarrassing, undignified, deluded old woman." Another running theme was concern for "bemused" Toby Anstis, who, as one blogger put it, "is having to be nice to the old lady". Yet this turned out to be errant nonsense when Anstis, who was voted off the show on Thursday, declared himself happy to have flirted with one of his schoolboy pin-ups.

It strikes me as interesting that this outrage coincides with a wave of opprobrium over teenage girls' sexual activity. The general message is that society seeks to control when women start to have sex and cease to have sex; there are widely held notions about an acceptable time span in which women can conduct themselves publicly as sexual beings, which just don't apply to men. Surely this is a terrifying anachronism some 600 years after Chaucer's death? That's why I'm backing Jan Leeming to win I'm a Celebrity and an army of toy-boy fans. Why on earth should a beautiful, clever 64-year-old have to feign asexuality to win general approval?