They are candid, provocative - and totally at odds with each other. Our resident 'sexperts' Nirpal Dhaliwal and Esther Walker offer conflicting advice on Londoners' sexual dilemmas...

Q: Earlier this year I had an illicit fling. Should I tell my husband? We've been married for two years...

ESTHER SAYS

What baffles me is not why you had an affair but why you bothered getting married in the first place.

In modern society, marriage is entirely optional. You no longer need to be married in order to have sex, in order to live together without being judged, for the social status of your children or to be entitled to the now-defunct married couples' allowance.

Getting married now only means one thing: that you want to make a voluntary commitment to someone.

You really want to say — to declare — in front of lots of people: “We are together and I won't cheat on this person.” If you don't fancy making that kind of commitment to someone, and you clearly don't, then why do it? No one would think the less of you for it — not seriously — and you'd save an awful lot of cash.

So marriage is now a mark of commitment only and yet you are able, before even your paper wedding anniversary, to give yourself physically to someone else (someone who didn't even mean much). Then what's the point of staying married? What was the point of ever being married?

I do sympathise: often, having sinned is as awful as being sinned against and I'm sure you're suffering.

But it doesn't sound to me like this marriage is going anywhere, even if you have convinced yourself that your fling was just a silly mistake.

The thing is, if you love someone, you don't cheat on them. It's not because you love them so much that you never fancy anyone else, that's just babyish.

You don't do it because the horror you feel at the idea of humiliating and betraying this special person stops idle thoughts of illicit fumblings from becoming a live act of infidelity.

It doesn't sound like there are any children involved so I can't see any reason why you shouldn't confess everything to your husband.

If you want to stay with him and are prepared to take your wedding vows seriously in the future, and if he is willing to forgive you, then you can start afresh and avoid being driven mad with guilt.

But if the confession leads to a split, you can think carefully about whether you are the marrying kind.

NIRPAL SAYS

The definition of infidelity in your relationship is basically whatever your other half decides it is.

Everyone has a get-out clause in a relationship and if you do anything to trigger that clause they will feel perfectly entitled to feel aggrieved or dump you - regardless of how trivial you think the indiscretion is.

Some people only object to emotional infidelity and can't bear the thought of you getting wrapped up in someone else but they might be able to tolerate the occasional meaningless one-night stand.

Others may be unable to even put up with you looking at other people, let alone fancying them or fumbling around with them.

Don't assume that your benchmark is the same as theirs, because it's very likely not to be. In which case, if and when either of you oversteps the mark, the stinky stuff will definitely hit the fan, with one of you feeling outraged and betrayed while the other can't understand what all the fuss is about.

A lot of people can handle the rare drunken snog. But never bank on everybody being this easygoing.

Some people might even regard it as treacherous that you look at porn, or flirt with other people at parties.

So you ought to ask them what their limit is then decide if you can live with that. If you can't, bail out and find someone with your outlook, or learn to live at least a few yards within the boundary that's been agreed.

Don't antagonise them by habitually sailing close to the wind.

Nowadays, you don't even have to touch anyone to be regarded as a cheat. Swapping dirty texts or having online or phone sex is more than enough for most people to feel betrayed. And as for hanging out and developing a rapport with someone you share a spark with - forget it.

Most people regard emotional intimacy as a bigger threat than empty, thoughtless sex. No partner wants to be competing for your attention with someone else.

Monogamy is a minefield. The only way to walk through it with relative safety is if you're absolutely clear with each other what the rules are.