People are often astonished when they visit our home for a family celebration, to find Sophie, my husband’s ex-wife and mother of his children, helping me set the dinner table. It takes visitors a while to figure out that (a) there is no tension in the air, (b) this is not a diplomatic encounter and (c) we are not practising polygamy. Sophie is a close friend of both my husband and I, loved not only by her own children but also mine, part of our extended family. She is also in a happy relationship, and we all get on really well with her boyfriend, Fred, who has two children of his own.

My husband’s divorce was like any other – full of pain and tears after 17 years together. At first, Sophie refused to meet me at all, dropping off the kids outside the gate, until, one day, her cheeky daughter set up an ‘accidental’ meeting between us, in the most well-meaning way. So we were forced to stand there facing each other, not knowing what to do, finally opting for a coffee to break the silence. That’s what my husband found on his return from work that day: the two women in his life drinking coffee and laughing nervously together. So he opened a bottle of champagne.

When I think about it, I realise the very fact that we were so unprepared helped us to see and connect with each other as human beings, outside of the imposed labels (the New, the Ex). Yet, there is another important factor underlying the friendship between us all – Sophie feels that the maintenance my husband pays her is fair and sufficient, so there are no financial hang-ups. This one was not easy – given that we have his children 50 per cent of the time, legally, he is not obliged to pay anything, yet he does, and above the going rate. And this actually puts our new family under a certain amount of strain at times. So, to my shame, I did not escape the usual ‘new wife’ thing to begin with – complaining about the size of child support.

I was wrong, and my husband was right in putting a good relationship before the money.

And I must admit that the sense of unfairness following my own divorce underlies the resentment I feel for my ex-husband, with whom I am not quite ready to make full peace yet after 12 years apart. According to a divorced couples classification*, my husband’s relationship with Sophie can be classified as ‘cooperative, mutually supportive and non-confrontational co-parenting’, which is enjoyed by about one quarter of divorced parents, while my relationship with my ex can be described as 'parallel co-parenting', with a relatively low level of conflict only because of disengagement (he emigrated to Australia). Guess which one is better for children long-term…

There is no magic bullet that can help us cope with the bitterness of the past (and sometimes the present as well), when the other party just doesn’t do the right thing. For example, I feel my own ex pays a lot less in maintenance than he's supposed to, and sees his children once a year at most. And as much as I would like to forgive him, I'm not there yet. So what can we do?

Some helpful ideas

● A ‘fair world theory’ is a strong cognitive bias, and should be treated as such. So when we keep thinking that things are not fair, it may be useful at some point to just accept that fact.

● Taking acceptance as a starting point, ask yourself: Given that situation as it is… (fill in the gap), what do I hope for myself, if relevant, and my children?

● As ridiculous as it sounds, try to find some benefits for yourself in the current situation. For example, OK, my ex doesn’t see his children, but at least I don’t need to see him either.

● Positive psychology advocates forgiveness as the key to moving on, yet, let’s face it, letting go of grudges when you’ve been hurt in the past is easier said than done. What worked for me is ‘half-forgiveness’ – writing a letter expressing everything I can forgive and leaving out everything out I can't. Don’t send the letter; it's just for your benefit, and can help you in the process of letting go.

● Finally, as far as your ex’s new partner, or your current partner’s ex, is concerned – try to view this person as they simply are, from a ‘clean slate’ perspective, without putting them into any mould. This person is not your story, so let them make their own story, even if it happens, or happened, to be with someone you love.

More inspiration:

Read The Good Divorce: Keeping Your Family Together When Your Marriage Falls Apart by Constance Ahrons (Bloomsbury Publishing, £12.99)

Visit positran.co.uk

* Hetherington, Bridges and Insabella, 1998

Dr Ilona Boniwell is our family expert and one of the most respected positive psychologists in the world. She lives with her husband, their toddler and four teenagers. Got a QUESTION for Ilona? Email ilona@psychologies.co.uk, with ‘ILONA’ in the subject line