Forget the image of a mistress as a man's plaything. Today's 'other women' not only know exactly what they want, but how to get it...

Society's stereotypical mistress looks something like this: the predatory man-eater with a taste for married men, the sad loser waiting (and praying) for the phone to ring, or the commitment-phobe only wanting to have her cake and eat it. Few beleive that mistresses enjoy the unconventional set up because they can enjoy a relationship on their own terms.

But today's mistresses don't learn about 'the wife' moments after the first bonk, when he mutters something about not being understood at home. Modern mistresses already know - and accept - that he's hitched.

My friend, Sarah, frankly admits, 'While I was the 'other woman', there wouldn't be another 'other' woman. I knew the pain of being cheated on because my boyfriend of 11 years dumped me for my best friend, so I never wanted to feel that vulnerable again. This way, I was in control.'

When she started the relationship her close circle of friends (including me) had been supportive, but secretly puzzled. What was our elegant, intelligent friend doing with this man? And if it wasn't bad enough, he was also a celebrity, and he had children.

The bitter irony in Sarah's case is that it turned out she wasn't the only 'other' woman. The man was revealed as a double love-rat when another girl went to the tabloids about his fling with her. But when the love-cheat tried to leave his wife for Sarah, she did another decidedly 'unmistressy' thing. She told him she didn't want him.

'I panicked because I realised I didn't really want the commitment. I only wanted to prove I could get a married man, but when he wanted to be with me full-time, I didn't want anything more to do with him.'

While Sarah's reaction devastated her married lover, chartered counselling psychologist, Susan Van Scyoc, says her reaction can be fairly typical of a modern-day mistress.

'Many mistresses actually enjoy the affair because they can keep their independence, knowing there is not going to be a 24/7 commitment,' she reveals. 'They get the fun and intensity without the smelly socks and laundry. So, if they are actually faced with a full-on relationship, a mistress will often bolt for the door.'

Like Sarah, another friend of mine - 33-year-old Katherine - knew that her boyfriend was married right from the start. She's been having an affair with him for the past three years. They started out as friends ten years ago and, despite Katherine trying 'to keep the padlock on my pants', they slept together at a work party.

'It's a terrible cliche, isn't it?' she half-laughs. 'I'd resisted for so long, but I finally caved in. David had always been off-limits because I knew he was married and had two small children. But then we started to work together and I started seeing him in a different way. When I finally slept with him, I knew I had crossed an invisible line - one there was no going back from.'

When David's wife confronted him a year into the affair, he admitted to his adultery straight away. But rather than throw him out onto the street, she agreed to turn a blind-eye to his relationship with Katherine, if he stayed for the sake of the kids. The unconventional arrangement worked to begin with, but two years down the line, Katherine admits it's starting to wear her down.

'We have a lovely time together - we have a laugh and I love him to bits. But I miss not being able to do the spontaneous things. Some mistresses are quite happy with what little bits they can get, but if David was to turn up on the doorstep with his kids, I would be over the moon.'