The problem John’s ex-wife was threatening to prevent him seeing his 12-year-old son if he included his girlfriend in any contact. What particularly incensed John, 35, was that she had moved in with the man for whom she had left him, with no discussion or apparent thought for his feelings about their son being brought up by this new man. But she insisted that she would stop contact if he even introduced their son to his partner.

The bigger picture Separated couples, particularly those united by a shared child, often find it really hard to sever the connection. Some continue more attached by conflict than they ever were by love. It’s a curious fact of separation that the partner who initiated the break — by having an affair, by suing for divorce — often finds it harder to let go of the bond. The feelings of rejection that might have led to the split, and those of guilt at having taken that step, often continue long after the relationship seems to be over. Lasting jealousy and pain may be expressed in anger towards any new partner.

The solution It would help, I said, if John first considered this new relationship. Was it likely to last, if not for ever (who can say?), but for the foreseeable future? It did his son no good at all to have a succession of new faces introduced as someone significant, only to disappear. Children of divorce have enough loss to struggle with without adding more, and it was possible that his ex-wife was putting forward not only her own anxieties but their son’s too. If John decided that his girlfriend was going to be part of his life, though, then she was also part of his family and his son and ex-wife needed to deal with that.

Trying to get this across face-to-face may end in an argument. What John could do was to write a letter to his ex. He could begin by expressing sadness at their separation, acknowledging the good times, and thanking her for the best gift of all, their son. He should say that he is sure that both of them have their son’s best interests at heart and that they should therefore manage any disagreements without conflict. Just as he was sure that her partner, their son’s stepfather, was committed to doing the right thing, he knew that his new partner was too and should be involved as they all were in doing their shared best for their son. It might help to thrash this out with some help so I suggested he made an appointment with a mediator, and invited his ex to join him there. Once they had come to some understanding, it would also be useful if both their new partners joined in the discussion. After all, both of them would equally be part of this new extended family.

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