Are we all love rats?

"For me, it's never going to be about one relationship... life is a series of relationships..."

This is, apparently, what Sam Mendes said to Kate Winslet whilst ending their marriage.

Alongside Mark Owen, Tiger Woods, Ashley Cole and Jesse James he is joining a long line of celebrity men for whom one woman, it seems, is not enough.

All this has got me (and the media) thinking about fidelity. Is it over? Can one person commit to someone for the rest of their life?

I'd like to think so. It may be me being hopelessly naive but I believe that, for some, there is one person. What I don't believe is that that one person is everything.

Yes, life is a series of relationships but they don't necessarily have to be sexual. I despair at women abandoning their friends for a new man or those who ditch their career the moment they get a whiff of marriage. I believe these women are not only damaging to feminism today but also are damaging their own relationships in the process.

Looking at successful relationships I notice one thing in common: hobbies. Something else to talk about. Other relationships to stimulate you, be they with your boss, your best friend or your trainer. It's not a groundbreaking theory, it won't sell millions of self help books but I do think it is the key to making a relationship last - letting other people in.

So, what if the people you let in are sexually involved in your life? Is this a bad thing?

In the case of the above men, yes it is. You only had to take one look at Mark Owen's wife Emma's face in the papers to see how truly devastating this was to her. This wasn't just sleeping with other women - it was betrayal. It was breaking everything he had ever said to her.

My parents began their relationship as an open one, they didn't believe in fidelity and didn't think that sex was something only to be shared between man and wife. However, my Dad told me once that despite this agreement he never slept with anyone else. Neither did my mother.

However, had they crossed that line it would have been an OK one to cross. Because the betrayal wouldn't have been there. I've never had any experience of an open relationship nor have I ever spoken to anyone in one and I'm sure they have their problems. But I doubt that feeling of complete let down, of being deflated and broken by the one person you trust isn't there. Because there is no need to deceive.

I'm not saying I'm about to run to my boyfriend and suggest we sleep with other people because I know that wouldn't work for us. I can't bear the thought of him being with someone else.

However, as much as that thought wounds me the one that makes me feel even worse is the thought of me cheating on him. Sometimes I picture his face if I ever did cheat on him - it makes me feel like I'm collapsing inside. And I know I could never do that to him.

We joke about the famous 'list' - the 5 celebrities that you could sleep with and not get into trouble - but, in reality, if Keith Flynt of Prodigy fame (an odd choice, I know!) came up to me and suggested it, I couldn't do it despite being 'allowed' to.

For after 5 years with the same man, having gone through everything we have, I simply cannot imagine being with someone else. In our years to come together I am sure we will go through more problems, more glitches and more fights and I know that at some point we will both be tempted to cheat. But at the same time we will live through so much more happiness. And those moments, those future moments, the present moments just aren't worth the risk.

I do hope that this discussion in the media is shining a light that all relationships are different. As are all love 'rats'. Everyone betrays the ones they love for a different reason, maybe for some it isn't betrayal at all.

I hope this new decade brings about a more openness to different structures of marriage, the different ways we love. And that, hopefully, in the future, if someone needs to go for sex elsewhere they can. Without leaving a devastating trail of heartache behind them.