Editor-At-Large: Let's be honest – there are far worse things than adultery

My goodness, is there something in the water? Open a newspaper, turn on the radio or the television and it's impossible to avoid middle-aged, successful men caught with their pants down. From sportsmen, actors and politicians to bankers – what a motley gang of cheating, lying, deceiving cads. Maria Shriver discovers Arnie Schwarzenegger has not only sired a lovechild with their housekeeper, but the timing couldn't have been more insulting: the little boy is almost the same age as her own son. Her adulterous husband hadn't even bothered to leave the family compound for his extra-curricular activities.

Thanks to parliamentary privilege, we know why Sir Fred the Shred sought and obtained an injunction to protect his privacy: he had apparently been conducting an affair with a female executive at work, contrary to company policy at the Royal Bank of Scotland. The former head of the International Monetary Fund is electronically tagged and under house arrest as he awaits trial in New York on charges of sexual assault. And every day brings further revelations about the sexual preferences of this once-confident predator.

Back in the UK, Energy Secretary and millionaire Chris Huhne, who may or may not have asked his long-suffering wife to pretend she was driving his car when it was clocked speeding, is another high-flyer who combined wife and family, career and sexual friskiness. Dumping his wife for his mistress (like Arnie, he barely left the compound as she had been working for him) is this stud's modus operandi: it turns out he'd already summarily discarded another mistress when he decided to stand down as a MEP and run for parliament.

Meanwhile, Twitter and the internet throb with gossip and innuendo (everyone loves a good mystery) surrounding the privacy injunctions obtained by famous men to prevent their families, fans and sponsors hearing about their down-market taste in floozies.

It seems there are a lot of randy men around. Even dear old living legend John Simpson tells an interviewer that, far from being embarrassed about the number of elderly BBC male presenters who have children with women young enough to be their daughters, he's positively bursting with pride.

On the face of this evidence it could seem as if infidelity is something men, rather than women, instigate. Wives run homes, breed, fit their careers around their husbands, and ensure that dinner is on the table at the appointed hour. If the marriage implodes, wives always get traded in for a younger model. Rare is the man who marries for a second time and chooses a female of his own age – ask either Dimbleby brother for starters.

All the same, I don't think that a rash of media stories about high-profile philandering proves that men are naturally more unfaithful than women. Quite the opposite. We are better liars who naturally multi-task. It's something we can do without thinking. So we're better equipped to have affairs without anyone finding out. We compartmentalise our sexual and emotional life. If we have sex with someone it doesn't mean we want to be around them full time. In short, modern women behave much more like men than we ever own up to, especially if we have a decent job and financial independence.

Once, short lifespans meant we married young and died after a couple of decades. Now, we could be stuck with our partners for 40 years. No wonder so many of us are unfaithful – it's just not natural. Sociologists say that infidelity has increased among the fiftysomethings. They probably can't face spending the rest of their lives having sex (or, not having enough sex) with only the person they married ages ago. Why not make marriage certificates renewable every 20 years, a bit like warranties or guarantees when you buy a car or an expensive gadget?

Gay couples are far more upfront about their sexual needs. They don't make such a fuss about fidelity. Surely heterosexuals need to stop pretending that adultery is a cardinal sin.

Could married straights learn from gay relationships? If we talked more, maybe we wouldn't stray. And if we do have the odd fling, it needn't be the end of a relationship. Men and women need to be a bit more honest about adultery. It's not that important.

Queen Mary is no answer to our high street woes

As Mothercare announces that it is closing 110 town-centre shops, and retailers signal more sackings as sales figures fail to improve, can wonderwoman Mary Portas work miracles?

The queen of shopping is to head a review into our tatty, lacklustre high streets. David Cameron said: "I am confident that her straight-talking, no-nonsense approach will help us create vibrant and diverse town centres and bring back the bustle to our high streets." The appointment is just another example of a government that has run out of ideas chasing a high-profile expert.

The Yorkshire Post asked: "Has he ever been to Rotherham town centre on a wet Thursday afternoon?"

Economists don't expect spending to return to pre-recession levels until at least 2013. What can Mary hope to achieve? Supermarkets and out-of-town shopping malls killed the high street long ago – and Mary was an adviser to the Westfield shopping mall in west London. A second mall has been built near the Olympic stadium.

Mary is paid by big retailers, so how can she truly represent the interests of small traders forced out of business by high rents, rates and city centre parking charges?

Emin speaks for many women

Tracey Emin is a friend, so I'm biased, but her impressive show at the Hayward Gallery should silence carping critics.

She's the modern equivalent of John Bunyan and his Pilgrim's Progress, or Samuel Pepys and his diary. Her emotional journey through life in minute detail has few characters – Tracey, some birds, Docket the cat – and the names (never the faces) of men. Her work touches young women because it expresses our "all about me" world.

People who have never met her relate to these almost embarrassingly intimate expressions of feeling discarded and worthless. Tracey has given up thinking Mr Right will come along – and, deep down, a lot of women accept they're in the same boat.

Why London is the stage for me

Last week was truly memorable – two evenings of bold and brilliant musical theatre. London Road at the National takes conversations with Ipswich residents about how their lives were changed when five women were killed by a man who briefly lived in their street.

Alecky Blythe weaves their stories into a poignant drama, but what lifts everything is the music by Adam Cork, which uses the natural cadences of the human voice in a very original way.

At English National Opera, Terry Gilliam brings his prodigious imagination to an ambitious staging of The Damnation of Faust by Berlioz. Gilliam's trademark techniques, the plundering of history and extravagant posturing, work to perfection.

This is ENO taking risks and winning. Both shows remind me why I can't live anywhere but London.