Carla Bruni and President Sarkozy: Why are we such passion killers?

AS public displays of affection go, the pictures of Carla Bruni snogging President Sarkozy during their state visit to the UK could have been a lot worse. In her demure Dior suit and pillbox hat the 40-year-old former supermodel turned singer and new first lady of France bore more than a passing resemblance to Jackie O as she leaned in, her lips puckered up seductively, for her next photo opportunity.

She had already won a legion of male fans when Christie's put a nude portrait of her from her modelling days up for auction just as she was arriving in the country looking, quite superbly, as if butter wouldn't melt in her mouth.

She could therefore have been forgiven for presuming that a minor session of tonsil hockey would only add to her allure. As it turns out, though, getting your kit off in public is more acceptable in this country than giving your loved one a bit of a smooch.

The honeymoon period that the new Madame Sarkozy had so thoroughly enjoyed with the British people finally came to an end over, of all things, her public snog.

Something similar happened when my younger brother decided to bring his now ex-girlfriend, and also a Page 3 model, home for the first time to meet the family.

I can only put it down to nerves – his, not hers, as she seemed to be in her element – but no sooner had we sat down to eat than they were playing footsie under the dining room table.

I know this, because at one point my foot got in the way. It was a tricky situation as my mum had just launched into a polite line of enquiry about the ins and outs of working as a topless model, so I decided not to mention anything, and in the process left myself open to the unwelcome attentions of a six-inch stiletto for the next 45 minutes.

My brother is the apple of my mum's eye, so while she may not have completely understood his girlfriend's chosen career, in the face of her baby boy's starry-eyed infatuation, she was more than prepared to be won over by the ensuing tales of photo-shoots and fake eyelashes.

It was only after they started snogging over her carefully created soufflé that her indulgent smile froze. When it comes to public displays of affection, there seems, for the vast majority of the population, to be very little middle ground. Some couples do it, others never do it and onlookers either abhor it or adore it.

This is despite the fact that we're living in a world of blatant exhibitionism, made up of blogs, online personals, lads' mags and YouTube, where almost anything goes – and often does.

So why is it that we disapprove so much of the fact that the Sarkozys can't keep their hands – or their adoring gazes – off each other. They look like two people who simply can't believe their luck, so surely we should be happy for them?

It could be that it's something to do with our national psyche. A friend of mine recently returned to Edinburgh after living in Spain for a couple of years. Hot on her heels was her new Spanish boyfriend with whom she is deeply in love.

As a couple they'd been used to taking long romantic strolls hand-in-hand along the beach, and in the evenings would dance closely under the sweetly-scented lemon trees while local townsfolk looked on teary eyed with emotion as they remembered what it was like to be in the first thrall of new love.

Well, it went something like that anyway, and certainly she was brought down to earth with a jolt when, on being reunited with her amor at Edinburgh Airport, a passerby screamed "get a room" when faced with the prospect of their tender reunion. There's nothing like a spot of public abuse to take the shine off a romantic moment.

It would make more sense if public reaction depended on who was doing the kissing. You'd think the prospect of Carla Bruni getting a little hot under the collar would be a more tempting one than, say, that of Wendy Alexander in the throes of passion – or indeed your own brother. But it doesn't seem to matter.

When presented with the vision of two people who are so overcome with affection for each other that they can't help but throw caution to the wind and kiss each other's faces off, detractors of public displays of affection just can't take the horror.

Admittedly, if the whole world was in a permanent state of loved-uppedness it might be a bit much to take. But public displays of affection happen, on the whole, when people just can't help themselves – and thank goodness for that. Surely it's better to live in a world when we get a little carried away sometimes, than one in which we don't.