Last year, at 38, I met a wonderful man. He made promises and shared big hurts: his lifelong fear of commitment, daily temptation by girls (he knew they weren’t the answer) and years of therapy. Two months later, over dinner, he told me he fancied the waitress and wasn’t sure I was right for him. I was devastated. He sent a loving letter asking for forgiveness. We talked about the waitress and “other girls”. He was adamant this was not something he wanted to act on, but something he needed to be open about. Then he disappeared for weeks. When we met, he was very cold, but invited me to Paris. Weeks later, he said he loved spending time with me but feared I was too old to have his children and that he had a “childish dream” of marrying a more stunning-looking woman, like Cindy Crawford. He said, “I don’t feel it’s over – I see us together in five years, but don’t know how to get there.” He is gone now, and I need help to move on. I blame myself. Would you say a little something to girls like me, dumped by someone with whom I felt I had a wonderful bond and exciting future?

Yes, I will say a little something. Take off those rose-tinted glasses. When a man is carrying a large sign that says, “Danger. No Entry”, pay attention. Don’t think you can change him. Don’t think he wants to change. If he did, he’d have done something about it (after all those years of therapy) and not picked on an innocent such as you. He’s not asking to be understood. He’s asking to be fixed. He wants unconditional love, no matter how badly he behaves.

Maybe his mother never forgave him for the natural self-obsessions of a child, or maybe he was never loved, so he needs to test every woman to the limits of forgiveness. Or maybe none of that is true. For whatever reason, he is a black hole of need, and that black hole will drive him to ever-increasing cruelty. Forgive one misdemeanour, and he’ll throw another at you. He’ll hurt you, just to prove his power (the waitress at dinner), then beg forgiveness because he has to be the centre of your attention.

Once he’s got you hooked again, he’ll manipulate you into fake emotional intimacy (“I’m so flawed, and only you understand”), but reserve the right to tell you his adolescent fantasies because it keeps you on your toes (“I won’t shag other women, but I’m going to tell you every last detail, just so you know I could – and might”). What he’ll never do is take responsibility for his behaviour.

You did not have a wonderful bond with this man. The only person he has a bond with is himself. He’s so narcissistic that it’s bordering on a disorder. That may sound unduly harsh – I wish I had space to print every example of self-obsessed cruelty listed in your very long letter – but perhaps the brief insight here is sufficient to remind you. A man who tells you you’re too old to have his children – note the “his”, here – and too unattractive is not a man, but a sad, damaged boy. Teenage boys have delusions about marrying Cindy Crawford; healthy, mature men do not.

He’s never going to commit, to you or to anybody else, because no woman is ever going to be good enough. Why? Because he doesn’t feel good enough himself. I know his charm and confidence make it appear otherwise, but narcissists construct a massive ego to defend a shatteringly fragile self-esteem. It’s a fatal combination, usually marked by manipulative charm and relentless cruelty.

I suspect your need to be loved is so great that you’re blind and deaf to reality. You see the charm, hear the false promises and then dismiss the hard evidence and blame yourself for his behaviour. A report from the University of Georgia describes the type of person likely to be attracted to men such as your ex as co-narcissists. “[They ] accept blame readily, are eager to please, defer to other’s opinions, and fear being considered selfish if they act assertively.”

You deserve much better. To move on and have healthy future relationships, you need to look at your emotional make-up. You may believe that you’re not worthy of love, so you accept any crumbs thrown your way. It may be that you don’t understand what makes a healthy relationship. Perhaps you need to look at the way loving people behave towards one another. Perhaps you might think about some counselling, or do some reading around the subject.

But, whatever you do, don’t believe it is your fault. If he were stealing money, we’d call him a con artist, but in this case, it is your heart, and a heart is a great deal more precious, as well as being irreplaceable, so look after it by absolutely refusing to connect with him. That line “I see us together in five years’ time” is not a promise. It’s a threat. If you don’t cut him off completely, he’ll go on hurting you and seeking absolution until he’s crushed you into the ground.

Helpful reading: Why Is It Always About You? The Seven Deadly Sins of Narcissism by Sandy Hotchkiss (James Bennett £7). You Can Heal Your Life by Louise L Hay (Hay House £9.99)

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 letters personally

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