Beauty is a gift that ought to come with a caveat: a warning sign stating that while being gorgeous might sound like fun, when it comes to relationships, oh boy, are you in for a rough time.

I should know. You can call me immodest, vain even, for admitting so freely that in my youth I was good looking. But then, I believe that had I not been so beautiful, I might still be married to the man I once loved.

The fatal flaw in our relationship was I blossomed to become so much better looking than he was. My poor ex couldn’t cope with living in my shadow and constantly felt jealous and insecure.

Julia Stephenson married in 1989 aged 26, but 18 months later it was all over. She writes: 'Gone, because someone had flattered me and seduced me and, stupidly, I didn't have the backbone to say 'No'

Meanwhile, I had my fickle head turned every which way by the gorgeous men who stepped over my poor, plain accountant husband to flirt with his perky young wife.

I ended up leaving him for one of his rivals: a banker with blond hair and chiselled features who was introduced to me by a female friend.

I had married in 1989 when I was 26 — I genuinely believed my husband was the love of my life — but 18 months later it was all over. Gone, because someone had flattered and seduced me and, stupidly, I didn’t have the backbone to say ‘No’.

She left her husband for one of his rivals, a banker with blond hair. Pictured, Julia Stephenson on her wedding day

Needless to say, my lothario soon gave me a taste of my own medicine, driving me insane by chatting up other women.

Suddenly I was the insecure one, constantly asking: ‘Who was that woman flirting with you at the bar?’

After a few agonising months, I was left nursing a bruised ego when he moved on to someone new — and yes, she was gorgeous.

Poetic justice, you might say. But I am far from the only attractive woman to have messed up her marriage by being too pretty for her own good.

A study published this week grimly notes that being beautiful is a ‘relationship liability’.

Researchers at Harvard University — like gossip mag columnists — were debating why Hollywood power couples, such as Brad Pitt and Angelina Jolie or Tom Cruise and Katie Holmes, rarely go the distance.

The latest example is Scarlett Johansson, who filed for divorce from her second husband this month and has frankly stated that monogamy is just not for her.

The researchers found celebrities were much more likely to be divorced than plain old Mr Smith, and had shorter marriages, too.

Pictured, Julia with her current partner, Steve, a builder. She writes: Being attractive throws temptations and opportunities your way. Sadly, when coupled with youth, it is a toxic combination'

Further research showed it’s not just the rich and famous — it’s all good-looking types.

They asked women to judge the attractiveness of 238 men from a high school yearbook. The most attractive were more likely to have had short marriages and be divorced.

Now, I don’t need a Harvard professor to tell me why that is. Being attractive throws temptations and opportunities your way. Sadly, when coupled with youth, it is a toxic combination.

The fact I was attractive meant I was constantly surrounded by men ready and willing to distract me from the path of true love. The more offers I got, the more convinced I became that the grass really was greener on the other side.

Julia fell into a vicious cycle of doomed relationships until she was in her 40s. She writes: 'As a beautiful woman, I never had that fear I would be left alone'

It led me into doomed relationship after doomed relationship, a vicious cycle that lasted well into my 40s.

When things started to go awry with a boyfriend, I never felt remotely inclined to try to work through any problems. I simply moved on to the next man.

As a beautiful woman, I never had that fear I would be left alone.

There was always another charming, handsome replacement waiting in the wings to offer me the heady excitement of a new relationship.

For example, one afternoon I walked out of the hairdresser’s with a friend, only to have a gorgeous young man screech to a halt in his open-top Ferrari in front of me. ‘I couldn’t have lived with myself if I’d driven past you,’ he said. ‘Will you come to the polo with me on Saturday?’

Pictured, Julia Stepenson with her father Tony Brown in 1999. She writes: 'My father had the dark, brooding looks of the man in the TV Milk Tray advert'

Before I had the chance to think, my friend had accepted for both of us. That weekend was spent drinking champagne with the attractive stranger and his wealthy friends. My boyfriend at the time — whoever he was — was forgotten.

On another occasion, I was running to catch a flight to Martha’s Vineyard in the States when a handsome older man stopped me, gave me his business card and simply said: ‘You’re beautiful — please call me.’ And I did. I now struggle to even recall his name.

As soon as any liaison hit a stumbling block, I’d be off to pastures new. One, I recall, ended because I refused to go away on a shooting weekend (I’d become a vegetarian). It was easier to walk away than try to fix the problem.

I suspect that had I been forced to stay and work on it, my life might be much happier.

As Dr Christine Ma-Kellams, lead author of the Harvard study, puts it: ‘We all value physical attraction, but it may make people who are unhappy in their relationships more likely to pursue alternative relationships and so perhaps it is not always a good thing.’

I have no doubt being really good-looking can be a curse when it comes to matters of the heart.

My parents, Anthony and Rosamund, were stunningly attractive. My mother was a glamorous blonde bombshell, the daughter of a baronet who was a food company magnate, and she looked like Julie Christie.

My father had the dark, brooding looks of the man in the TV Milk Tray advert.

Julia grew up listening to her parents arguing. She met her trainee accountant husband (pictured) in 1982, when she was working as a chalet girl in Switzerland, aged 20

They married young in the Sixties, just as a new era of sexual liberation was dawning. Social constraints no longer provided much of a bulwark against having your head turned when temptation came your way.

I spent the early years of my childhood with my ears ringing to the sound of their arguments as accusations were liberally thrown.

Time and again I’d watch through my window as my mother screeched off in her sports car looking for solace; she knew damn well that her husband wasn’t above doing the same. Little wonder they had split up by the time I was nine.

She writes: 'I was a late developer as far as my looks were concerned — throughout my school days and early 20s, I had very little self-confidence'

It was a pattern of behaviour I might have escaped had I remained the rather plain Jane I was when my future husband and I met in 1982, when I was a 20-year-old chalet girl in Switzerland and he was a 22-year-old trainee accountant.

I was a late developer as far as my looks were concerned — throughout my school days and early 20s, I had very little self-confidence.

So, when along came a lovely man who treated me well and clearly loved me dearly, I felt incredibly lucky to have him.

He wasn’t much of a looker, but then neither was I, so we seemed well matched. It was only around the time that we married that I suddenly began to blossom. My gangly limbs became shapely; my features somehow more refined.

I became fixated with the idea that I’d made a dreadful mistake in settling for someone whom I had mistakenly assumed was the best I could hope for.

For the first time in my life, men were falling over themselves to talk to me, even when I was with my husband. You can imagine the ego boost that gave me. Unforgivably, I chose to ignore how much hurt this would cause.

I remember soon after we married I was at a dinner party sitting next to an attractive male friend and realised with great regret I’d never have the opportunity to go out with another man again. There was a frisson of chemistry between us. Later that evening, I danced with him, despite seeing the pain on my husband’s face.

Pictured, posed with models as four eligible men. Julia writes: 'For the first time in my life, men were falling over themselves to talk to me, even when I was with my husband'

At home, he’d find me trying on tight clothes that showed off my figure and be horrified.

‘You’re not going out looking like that,’ he’d bark, before insisting I return them to the shop.

‘You want me to look middle-aged before my time,’ I’d snap back, before flouncing off — just as my mother had done when I was a child.

After just 18 months our marriage ended when I left my husband for the banker who wooed me right under his nose.

And so it continued, for decades. As my looks held up, the romantic opportunities kept coming and my still pretty head continued to be turned.

It was only when middle age struck, bringing with it at last a rather more mature frame of mind, that I began to tire of it all.

I genuinely didn’t want to still be careering from one meaningless relationship to another in my 50s, and besides, I was long past the age when I could be seen as a ‘dolly bird’ or ‘arm candy’.

She writes: 'I won’t pretend to regret having been being beautiful, but I can’t help thinking my life would have been much more stable had neither I, nor my parents, been so attractive'

Ferraris no longer screeched to a halt in the road — and it felt like relief.

So I changed my ways, and my expectations. I was 42 when I met my partner Steve, a 60-year-old eco-builder.

He is as far removed from the playboy type I used to go for as you could imagine, and I hope he’ll forgive me when I say less conventionally good-looking, too.

I won’t pretend to regret having been being beautiful, but I can’t help thinking my life would have been much more stable had neither I, nor my parents, been so attractive.

All that temptation and flattery turned our heads, meaning we were always less than satisfied with what we had.

It might well be true, as my friend’s analogy suggests, that plain people stay together because they have little choice in the matter, but perhaps their lives are happier as a result.

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