Five years ago, I met a man I was very attracted to. I didn’t do anything about it, as we were both married, but we met for coffee every Tuesday and it was the highlight of my week. Then I found out we were moving away, and told him how I felt. Over the next two months, we had an intense affair. The sex was great, but we spent more time laughing and talking than making love. Neither of us could bear the thought of breaking up our marriages, so I left. I missed him so much, it was like a physical pain. He missed me too, and couldn’t eat or sleep. Gradually, it got better. We kept in touch by e-mail every few months. Today, I received an e-mail saying that he and his wife have separated, and that he wants to see me again. I know that if I go, I’ll stay. We both feel we were meant to be together. Should I give up everything for him?

A. I suspect that you want permission, not advice. You tell your story as if it is a grand romance involving star-crossed lovers, instead of a rather ordinary affair. I’m sorry if that sounds harsh, but a sharp dose of reality may be no bad thing in your situation. You can always dismiss me as a cynical idiot with no soul.

I’m interested by the contradictions in your letter, and perhaps in your mind. First, you say that you’re in love with your husband. Then you say you took a lover. Why? If you were so much in love with your husband, why would you look elsewhere? Please don’t say: “My life was great, but somebody came along. I didn’t want it to happen.” If it really was great, there would be no room in it for anybody else.

According to social psychologists, we are brilliant at the art of self-deception. It’s hard-wired into our genes. We can convince ourselves of almost anything. It takes enormous effort, and honesty, to see ourselves clearly. Your story is: “I can’t help myself. This is bigger than me.” I’m sure you believe that, but I’m afraid to say that I don’t. I do think that love can be bigger than us. I also think it happens very rarely. We convince ourselves because we want to believe it, or because we want an excuse to leave a situation. Or simply because we are in love with the idea of love — or love the idea of ourselves at the heart of a great romance. None of this may be conscious: we have to delve deeper to see what’s really driving us.

Let’s use honesty now. If you were supposed to be together, how have you managed to stay apart for so long? You left your lover and, although it hurt, it didn’t hurt enough to send you back. I know, you were doing the honourable thing. So what’s changed? Is it because he’s suddenly available? Is your marriage less happy than you are making out? Or is it because your attachment to this man is not actually real, but simply a romantic fairy tale to add excitement to an unblemished and fairly uneventful life?

You even paint yourself as the princess. You are “adored”. You are “very attractive and have had lots of offers”. None of which you accepted, of course, because your heart already belonged to somebody else. It sounds so charming. And not quite true to life, at least not in the sense that most of us are intimate with life. Even your payoff line is storybook drama: “Should I give up everything for him?” Let me put that another way: “Should I destroy everything for him?” It doesn’t have quite the same ring, does it?

I don’t feel particularly moralistic about this. Marriages break down. Lives change. We fall in love with people when we least intend it and out of love with others when we least intend it. But this much I know: a good marriage is a precious thing. You say you have wonderful children and a great family. In other words, you have years of history, a head and a heart full of memories, habits and funny, precious family rituals that can’t be replaced. They can, however, be smashed and sullied beyond recognition or repair.

You have to ask yourself, would the result be worth the damage? I don’t mean to your husband and children — I have no doubt the result would never equal the damage to them. I mean, would it be worth it to you? If you truly felt that you couldn’t exist in any meaningful state without this man, then he would inhabit your soul. And your husband would, long ago, have become a pale imitation of love. Yet you are still, as you put it, “happily married”.

What story are you telling yourself? Where is the truth? Where are the bad times in this too pretty picture? We cannot be truly intimate with somebody until we have shown them our darker selves. Have you? Can you? Would you? And would love deepen and mature as a result, or would it be too flimsy to withstand the onslaught?

I think, before you do anything, that you have to get yourself, your life and your lover into forensic focus. Stop telling it like a pocket-book romance and face reality. What would you be walking away from? What would you be walking towards? And is the journey truly worth it?

If you have a relationship question for Sally Brampton, e-mail sally.brampton@sunday-times.co.uk. In case of publication, names will be withheld. We’re sorry, but Sally cannot answer every letter personally

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