Standing in the hallway of the home she shares with her husband and their teenage daughter, Stephanie Burton drops her overnight bag on to the floor and calls out to her family.

She kicks the bag from her husband’s path as he comes to greet her and, at the same time, makes a conscious effort to push aside the events of the past 24 hours — a stolen night in a hotel with her lover — and return her attentions to family life. To reality.

Reality, for Stephanie, means being a loving wife and mother; the busy woman in the office who gets things done; the daughter her ageing parents turn to for help because she lives much closer than her two older siblings.

Bombshell FEMAIL survey reveals that one in five women have had an affair - and just under 50 per cent of their partners remain oblivious to it (stock image)

‘I just get on with it all, to the best of my ability and without complaint, because all those things are important to me,’ stresses Stephanie, 40, who lives with her lawyer husband Michael and their 14-year-old daughter in Manchester.

‘But there’s another side to me that I now realise was seriously neglected until I started having an affair 18 months ago. Part of me wants to shake off the burden of responsibility once in a while; to be seen as a sexual being, above everything else, for a few hours.’

It sounds hard to understand or accept. Yet the double life that Stephanie keeps a secret from all but her closest friend — someone she says has enjoyed the odd dalliance herself — is less unusual than you might think.

According to an in-depth sex and relationship survey conducted by Femail, one in five British adult women has had an affair — and 40 per cent of those have been unfaithful to their current partner.

What’s more, nearly half of those husbands and partners — 47 per cent, according to the women we polled — remain oblivious to the fact that they were, or indeed are, being deceived.

The shocking survey also found that 40 per cent of women had been unfaithful to their partners during the relationship (stock image)

Today, in the second part of our exclusive nationwide survey, we share the fascinating insights gained by talking candidly to more than 1,000 women of all ages about their sex lives, asking whether they’ve strayed and, if so, what they did to heal their relationship in the aftermath.

The results, and testimony from women like Stephanie, suggest that infidelity for women has as much to do with wanting a distraction from the mundanities of real life as physical thrills.

And it confirms just how dire and far-reaching the consequences can be for both parties.

Stephanie, a merchandiser for a large department store, is adamant she has no intention of leaving her husband. It would break up her family, cause heartache and disrupt a life that makes her broadly happy.

‘I love our home, we have a good social life, and I still have sex with Michael once a week or so,’ she says. ‘OK, I find him a bit dull after nearly 20 years together. He’s a workaholic and so consumed with his job that I often wish he’d find something else to talk about.

‘But I love him and can’t imagine spending my life with anyone else. In fact, I hoped our sex life might eventually be reignited by my affair.

‘I’d hate to spoil what we have, and I’m incredibly careful not to get caught. The fact I travel for work makes it easy to get away with the odd extra night here and there.’

though Stephanie’s lover is also married, she claims she doesn’t feel jealousy, or even guilt, towards his wife. ‘Neither of us wants anything long-term. If he announced he was leaving his wife, honestly I’d run a mile,’ she insists.

‘Maybe I should feel guilty that I’m betraying my daughter as well as her dad. But the way I see it, I’m happier at home, while my sexual needs are being met elsewhere. Isn’t that better?’

Of course, many people would disagree with this assessment. Yet Stephanie is extremely self-aware and says she regards her affair as totally separate from her marriage — an exciting diversion with, as she sees it, minimal risk. It’s become a way of nourishing a side to her that family life quells.

‘This is what so often happens in an affair,’ says psychotherapist Lucy Beresford, author of Happy Relationships. ‘Women can feel a little exploited, to varying degrees, in their real-life roles. They’re working hard at being a brilliant wife, fantastic mother, dutiful daughter, and pushing themselves at work, too — but something’s missing.

‘Having an affair becomes a way of attending to the part of their psyche that feels neglected, without the pain and disruption of walking away from their marriage.’

Lucy adds: ‘It is possible to overcome a sense of feeling neglected within a marriage, but you have to acknowledge it to yourself first.

Stephanie Burton, 40, from Manchester, said she started an affair so that she could feel like a 'sexual being' again as her husband is often consumed with work (stock image)

‘Sometimes, feeling abandoned or ignored by our partner is so horrendously painful we bury the emotion and “act it out” by seeking affection or desirability elsewhere.’

Viewed in this way, infidelity becomes about much more than sex — straying is a way of staying in the marriage without having to rock the boat by making it plain that certain needs aren’t being met. It softens the blow of feeling that your priorities so often seem to come after everyone else’s.

Psychotherapist Lucy Beresford offered her advice on why affairs take place

‘These don’t tend to be conscious conversations people have with themselves,’ says Lucy. ‘But, deep down, a trade is being made — the affair is what stops them from getting angry about what’s wrong with their life, so they don’t actually have to do something about it.’

There are, of course, many other reasons women are unfaithful: an affair can be an act of revenge on a partner who’s strayed first, or a way of expressing frustration at unreasonable behaviour.

For others, it can simply be a deep-rooted pattern of behaviour connected to low self-esteem, lack of care for others, or going back to destructive early relationships.

Or it can be entirely out of character, becoming part of an escape route out of a miserable relationship. This was the case with Rachel Morgan, a 38-year- old translator whose affair with a colleague, she says, provided the wake-up call that led to her ending a four-year relationship.

Rachel Morgan, 38, used an affair to help her get out of a miserable relationship where her ex was 'incredibly childish' and 'hopeless around the house'

‘Living with my ex was like being the mother of a grown man,’ she says. ‘He was incredibly childish, hopeless around the house, constantly wanting me to fix his problems for him. I’d stopped fancying him. We weren’t even having sex.’

Despite her unhappiness, Rachel, from London, didn’t feel a strong drive to leave her partner, who was the same age.

Until, that is, a work project took her away for several weeks and she began spending time with a male colleague. ‘I started to feel more mentally stimulated,’ she says. ‘We were having interesting conversations, and I found his company relaxed and fun.

‘When we started having sex, it felt inevitable, but it soon became about far more than that.

The survey also found that fewer than one in ten couples sought counselling after discovering that one of the partners had had an affair (stock image)

‘My lover was bringing out the best in me, and that made me look at my relationship and appreciate how much it was dragging me down. I realised I didn’t want to fix things. I wanted to start again.’

Extricating herself from an unhappy relationship in this way wasn’t intended — and it was painful for both parties — but, ultimately, the spotlight that the infidelity shone on Rachel’s relationship couldn’t be switched off.

‘An affair often forces us to look in the mirror and explore whether we like who we’ve become in our relationship,’ says Lucy Beresford. ‘Whether or not you get found out, it becomes a driver for change.’

Couples’ therapist Hilda Burke says that an affair can be symptomatic of other problems, and that it is possible to work through it if both parties are committed

Yet our survey — which looks beyond the number of confessions of clandestine affairs to what happens next — found that fewer than one in ten (8 per cent) of couples sought counselling after discovering one partner had had an affair, even though the emotional fallout is often extremely complex.

Couples’ therapist Hilda Burke is not surprised. ‘The thing that’s creating problems in a relationship needn’t be a lover — it can be difficult in-laws, work, an addiction, or even your children,’ she explains.

‘Certainly, in my practice, those tend to be the issues that people bring to therapy far more than wanting help following an affair.’

Is that an issue when it comes to working through difficult feelings after infidelity?

‘Not necessarily,’ says Hilda. ‘If a couple have the emotional intelligence to recognise that the affair was a symptom of bigger problems within the relationship and have committed to staying together and working at fixing them, then they may well be able to do that without therapy.’

Whether your marriage has been threatened by infidelity in the past, or you find yourself nodding along to some of the emotional motives for women to stray, the best cure for a lull in your relationship is to talk about it — and seek help if you are not satisfied.

Some names have been changed. Additional reporting: Samantha Brick