Your cheatin' heart

So which ones were the true feminists? The girls who ditched their two-timing blokes for the ultimate betrayal, or the ones who refused to let an affair destroy years of marriage? And what of the "other woman"? Can she truly be considered a feminist once she has cheated on the sisterhood? "I never thought in a million years I'd have an affair," says Lauren Rosewarne, a 29-year-old university lecturer. "I'm smart enough to know it won't end well.

"As a feminist who has worked in party politics and at universities for a decade, I have witnessed a multitude of marriages unravel due (usually) to the man's cheating. Until recently, I was adamant that hell would freeze over before I became complicit."

Despite her best intentions, however, she spent two and a half years in a relationship with a man who already had a partner. "It was very much this idea of 'my wife not understanding me', which was both a clich and an appeal in the sense that you find yourself potentially being able to be a solution to that; particularly if you see yourself as a problem-solver, which I do. 'I can fix this, how couldn't I not be smart enough not to?' Of course, it's not about smarts at all."

She was all the more intoxicated by the fact that the man in question claimed to be a feminist too, though a friend later reasoned that this was probably less a political stance than a strategy to meet women, while another maintained that men who claim to be feminists are all "bastards and liars". Nevertheless, she fell in love, made excuses to herself about why it was right, and when it eventually ended – "ambiguously" – she was both devastated and almost relieved. "I was lucky," she says now, "tyranny of distance meant it was impractical."

In an attempt to make sense of her situation, the lecturer at the University of Melbourne put pen to paper – though it's not a course of therapy she would recommend to anyone. "It makes everything a million times worse," she says. "You think you only have one thing to be upset about, now you have 100,000 more. Particularly writing about, for example, exploitation. I did not feel exploited during the relationship – I don't want to see myself as a victim – but in hindsight, if I was an outsider I would be more able to use those kinds of words."

Her research also revealed that infidelity is much more common than we realise. "Audiences are quite hostile to me," she says. "But one-on-one they're very willing to say, 'I was in exactly the same situation.' Everyone I speak to has either been in that situation or knows someone who has, but we don't tend to talk about it. It happens far more frequently than we care to acknowledge."

Some women even enter into an illicit relationship as a conscious act of feminism – "I'm entitled to sexual pleasure. He's made his own choices so I'm going to do what I want and what feels good for me, to hell with everybody else" – but that doesn't cut the mustard with Rosewarne. "And it certainly doesn't make you feel any less wretched. So the extent you will get liberation from that is very minimal."

But as a single woman, she was free to act in whatever way she chose; she was betraying no one, surely? "I think that's often the justification for women: 'Why should I care? I'm not doing anything wrong.' I think the difference is that you know the man has a partner, so as much as I'd like to say it wasn't my responsibility to look after his relationship – which I genuinely think it wasn't – I can't honestly absolve myself from hurting someone else. And if someone gets hurt and someone gets betrayed, then an affair can never be justifiable."

In fact, most of us would never choose to seek out an affair, she says, because the rewards are so slim. So why is it still happening in such large numbers? "I think it is to do with the impact consumer culture has had, and this idea that we're constantly being encouraged to upgrade and to change and to buy the absolute newest technology and to never be satisfied. And that idea of the mid-life crisis happening earlier because we're so dissatisfied with everything and we want more and we want better.

"Also, there's no reason to say no. Because in a culture that's not really driven any more by Christian values that may have had people saying, 'I'll resist,' where's the incentive to say no? But that idea of following your heart can be awfully repressive."

The constant round of celebrity affairs in the press also helps normalise infidelity and feeds stereotypes, she says. "That the other woman is always the one who tempted the man; if she wasn't there he would never have strayed, which is an incredibly sexist notion. It's as though a woman is the one who tempted him without him being the one who actually had to agree. And that's a very naive way to look at it – if it wasn't you, it would have been somebody else."

All we know about Monica Lewinsky, for instance, is that blue Gap dress; she is completely defined by that "and also by being in a subservient sexual role", says Rosewarne. As for who is to blame in this so-called love triangle, it is not simply the "other woman"; nor is it just the man who strayed. "Everyone must take responsibility for their own actions. The betrayed wife; I think she's wrong in the sense that she's not more outraged, that she silently swallows subordination. Is it okay to be treated like this?

"I spoke at a University of Edinburgh lunch, and one of the women said to me, 'There's a lot you can learn if you've been cheated on; you get to see the relationship in a whole new way.' And I just said, 'You're just learning how to swallow more bullshit.' I did the same thing, I've been in the same situation, but thinking about it in a new way just gives you another way of looking at being treated poorly."

In that case, can a couple ever recover from infidelity and make their relationship work again? Yes, says Rosewarne, if they decide that fidelity isn't the most important thing in their relationship. "If you've pinned everything that determines what you consider a successful relationship on fidelity, if that's crushed, either you have to re-evaluate your priorities or move on. But if it was never the most important thing to you, it's fine. I know myself, even though I experienced some betrayal, I still would have put up with it to stay with him, because I loved him more than I loved the idea of him being faithful to me.

"I was asked would I do it all again and I said, 'Yes, in a heartbeat,' because I enjoyed it. Even though it was horrible, I would never not have that. I want to say to other women in the same situation, 'Get out, it's only going to get worse and you're only going to fall deeper and find it even harder,' but by the same token how can I say I'm going to take that small amount of pleasure and throw it away?"

She talks about applying a cost benefit analysis to relationships, weighing up the pros and cons, but you can't do that with infidelity "because suddenly you value love or intimacy much more," she says. "You weigh that more heavily than if you said, 'Well, I'm a good person and I resisted.' In the scheme of things, that doesn't actually feel important. So the way you would do a cost benefit analysis in business doesn't apply to a love affair."

And when her relationship was over, Rosewarne had no desire to maintain contact with the man; that would have been far too painful. More surprising, perhaps, is the fact that she desperately wanted to speak to the partner he had betrayed. "She was the only one I wanted contact with," she admits, "because I thought she's the only one in the entire world who understands what it's like to be without him. But she's the one person who probably hates me more than anyone else in the entire universe."

Feminism today means different things to different people: from the hairy-legged lesbian clich to the strong, confident woman role, and everything in between. "If I go out and meet a guy, I would never say that I'm a lecturer in feminism because straight away that's a deal-breaker; I'm seen to be a ball-breaker. But there is no homogenous representation of feminism any more," says Rosewarne, "which I think is a good thing. I like the fact that it's not easily pin-pointed."

However, you might think that third-generation feminists would know better by now; that they wouldn't need to rely on a man or need a man to be happy and fulfilled. But that's just not the case. "There's that idea of compulsory heterosexuality," says Rosewarne, "not only being heterosexual but having to act on it – finding a mate and settling into something that feels like a couple."

The situation is not helped by the fact that the world appears to be designed for people in pairs. "When you pay for a single room, everything is so much more expensive. Recipes, meals – everything seems to be geared towards couples. Even when you go to a restaurant you're told you're going to be waiting longer than other people. You don't notice it until you're in the situation.

"Time doesn't dilute the need to be intimate with somebody," she adds. "So if they happen to be in a relationship I think that's a sad consequence, but I don't think that need to be coupled goes away just because we can go and open our own bank accounts or buy our own houses." r

Cheating on the Sisterhood, Infidelity and Feminism, by Lauren Rosewarne (34.45, Praeger), is available at selected bookshops and through Amazon (www.amazon.co.uk)love over everythingAngelina Jolie and Brad Pitt The couple now known as Brangelina maintained for years that they only hooked up after Brad and Jen had split. Recently, however, Jolie admitted that she had fallen in love with her paramour on the set of Mr and Mrs Smith, while he was still married.

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Camilla Parker-Bowles and Prince Charles Princess Diana said there were three people in her marriage to the heir to the throne – with Parker-Bowles being the "other woman". Charles met his now wife in 1970, and though they both married other partners, they remained close – with Charles admitting to adultery in an interview on Panorama.

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