I think I'm turning Lebanese

Men have it so easy. For most, the mid-life crisis amounts to little more than filling out the financing form for a new car or trying to hit on the office secretary. According to a new study, to be shared with the American Psychological Association in August, women have a much tougher time as they approach middle age. Rather than pricing up a Porsche Boxster, they seem to spend their time balancing hot flashes with a spontaneous change of sexuality.

The dating market is currently being flooded with with 'late-blooming lesbians' - women whose only previous brush with sapphic sensuality was occasionally hearing 'Constant Craving' on Radio 2. Suddenly, and without warning, they're strapping on (steady now) some sensible shoes and putting up their own shelves with a same-sex partner, leaving emasculated (but probably turned-on) ex-husbands in their wake.

As with most news stories, it helps that there are some celebrities who can be held up as examples - in this case Sex and the City's Cynthia Nixon and Mary Portas, Queen of Shops. Despite being entirely heterosexual throughout adulthood, they both decided in their forties that their furry cups runneth over.

As you'd expect, the coverage of this 'phenomenon' is suitably melodramatic - lots of references to illicit liaisons, bullied children and "irrevocable damage" caused to relationships. The Mail, in particular, makes repeated reference to the women's "devastated husband[s] and utterly bewildered children".

One husband in particular lashes out at his ex-wife, saying "I can only describe her actions then as incredibly selfish, because she put herself and her feelings first. Overnight I was left on my own with two impressionable young boys, who were totally bewildered and terribly upset, having to explain where their mother was." Of course, it's easy to overlook how often men put their wives in similar situations when they run of with younger women, but lesbianism makes for a convenient bogeyman.

Thankfully though, all the lesbians featured in the story are happy and contented with their new sexual identity, and have generally been able to repair the rifts with their families. What's more interesting is the question that this situation throws up regarding the fluid nature of human sexuality.

Gay rights advocates have always been keen to prove that sexuality is pre-determined. So the idea that a woman can choose to switch sexuality, the way she might bring out the summer wardrobe when the weather improves, makes for a troubling twist in the tale. Does the fact that women can 'select' their sexuality mean that it's a lifestyle choice, rather than a genetically programmed quirk of nature?

Dr Ceri Parsons of Staffordshire University believes that it's not as simple as that: "Generally people are more aware of lesbianism - so while it appears that there is an upsurge in lesbian relationships when actually it might simply be the case that they are just more visible. Historically psychologists have tried to pigeonhole people as homosexual or heterosexual but these categories are highly inadequate. Sexual preferences aren't always set in stone."

For the foreseeable future, experts will continue to compile reports, analyze statistics and test hypotheses to see if they can find the definitive answer. But they miss the point - finding happiness is what really counts. The only thing, in fact.