The names women choose to adopt for themselves often strike me as quite bizarre, especially when they derive from terms men use to denote women’s desirability. Such as “yummy mummy”. What does that mean — that being an ordinary mummy is revolting, but if you bimbify yourself sufficiently — bit of starvation, some highlights, heels — you’re okay? And Milf. I understand Milf used as shorthand by a certain kind of man devoted to certain kinds of websites, but I overheard yet another woman the other day saying she’d like to be one. She didn’t seem remedially stupid, but then you never know.

The newest moniker to join this happy parade is “cougar”. Cougars aren’t new — the term was first coined in America in the 1990s, but it’s now everywhere thanks to a US television series called Cougar Town, starring Courteney Cox Arquette, formerly the anally retentive one in Friends. As a result of its screening on ABC, women, it seems, are queuing up to call themselves cougars, although “total dingbat” might be more appropriate. A cougar is — well, a cougar is puma concolor, a mammal of the felidae family, native to the Americas, with a round head and erect ears.

In this context, though, a cougar is an older woman who dates younger men. In Cougar Town, Arquette plays a 45-year-old divorcée with a series of twentysomething love interests. “I hope this show is a huge hit and people love it,” she said. “Because I like playing this character more than any character I’ve ever played.”

I’m all for women celebrating being in their sexual prime and for the studios not giving all their plum parts to barely-legal ingénues. Hooray for sexual primes! Hooray for sex! Beyond that, though, I’m kind of stumped.

I’m 43 — roar — and I find the idea of having boyfriends only marginally older than my 17-year-old son a bit grim. Still, I suppose that if you’re forty-plus, female and frisky, younger men fit the bill nicely since they tend to be neither married nor broken and bald (interestingly, I’d be lynched for making this remark in reverse: “Oh yes, old blokes with very young girls, marvellous because they’re all single and innocent — it’s so modern, so refreshing, so empowered.”) But anyway: if older women want to shag younger men, good on them. Shag away, old ladies.

What bothers me, though, is the way in which women are no longer allowed (by anyone, themselves included) to be anything other than sexual. If you’re not up for it, you might as well be dead: get with it, nanna, flash us some cleavage. But what if, for instance, you’ve been reasonably happily married for a couple of decades and your children are grown up and you like Radio 4 and gardening and just pottering about? What if you’re clever and attractive and nice, but you don’t want to prowl around making big bifocal eyes at blokes young enough to be your children? What if married sex — I think we all know what I mean by married sex — suffices?

It’s the Emma Thompson v Madonna quandary: do you look lovely, live discreetly, help people — Thompson and her husband Greg Wise, a mere seven years younger than her, support a young Rwandan called Tindyebwa Agaba — or do you date models, go baby hunting in Malawi to show you’re a good person and get photographed for advertising campaigns looking as if you’ve recently orgasmed? I bet Thompson would rather chop off her head than refer to herself as a cougar; the same could probably not be said of Madonna.

The old-fashioned middle to old-aged state of contentment — tea, novels, sweet old Bagpuss of a spouse — used to be the thing that everyone aspired to. It was cosy, comfortable, familiar. I used to view my old age with extreme excitement: I was going to eat everything I wanted, make cakes, read piles of books and maybe have a pub. The question of who I’d be having sex with didn’t figure anywhere on my list.

Surely — surely? — you’re allowed to get to a point when you can just do what you like without having to worry about how hot you’re looking?

Well, yes, but only up to a point: the middle-aged to elderly world now seems to me to be split in two: cougars on the one hand, grannies on the other. Sometimes the cougars are grannies. It’s incredibly confusing. I don’t mean just to me personally, I mean in terms of society. The demarcations of age are eroding by the day and it’s not necessarily a good thing.

It’s interesting, the new age inappropriateness. It’s because we’re all going to live for so long — scientists recently announced that babies born now would live to 100 — and we haven’t quite worked out what to do with the extra decades.

We can’t reconcile what we’re like at 40 with what we remember our mothers being: it’s like being a different species, so we feel duty-bound to rewrite the book without asking what was so dreadfully wrong with the original. We take our inspiration from movies and sitcoms, so that what used to be a joke has achieved cultural dominance I’m pretty sure the caricature of the predatory older woman started as a gag in some American movie or sitcom, except now it’s become real. The thrillingly antique Mrs Robinson, as portrayed by Anne Bancroft in The Graduate, was in fact an un-cougarish 36. If the film had been set in our present day, she’d be gearing up to her first pregnancy.

On top of that, we’re so horrified by the idea of “old age” that we run screaming in the other direction — “I’m 73 years young! I’ve still got good legs!” — instead of embracing what it might have to offer. I don’t remember my very beloved grandparents writhing about in OAP misery: as far as I could see, they had a lovely time by adhering to the tried and tested method: when you’re young, you’re looked after, when you’re in the middle, you look after other people, when you’re old, other people look after you again. (As opposed to when you’re old, you run about shagging people you met on the internet.) The more I think about it, the more I find old-school old age massively appealing. Never mind the cougars — let’s hear it for the ... what shall we call ourselves? Possums, I think; patron saint: E Thompson.

We've been casting around for a new pet recently, due to my daughter’s extreme love of other people’s guinea-pigs, and it turns out we’re spoilt for choice.

Guineas aside, she’d very much like a micro-pig, which is exactly what it sounds like and is about 8in long, extremely sweet-looking and will set you back £650.

Or a micro-hedgehog, aka an African pygmy hedgehog, equally adorable and exactly like a creature from Sylvanian Families come to life (£150).

I made the fatal mistake of Googling for images of both these animals and even my lumpty teenage sons started making cooing noises. I wondered if there was such a thing as a mini-bear (there isn’t — I checked, like a mad person).

Cuteness aside, though, I worry about the miniaturisation of animals for our own enjoyment and convenience. I love the idea of sticking my mini-pig in my handbag when I go for a pint of milk, but there's something not quite right about it: pigs aren’t supposed to be mini, they’re supposed to be terrifyingly huge.

Maybe we’ll just get a fish.

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