If your former spouse has Parental Responsibility (PR) for the children (see questions above) then they have a general right to know how the children are. Even if they do not have PR they could probably apply to the court to seek an order for this, and in any event will no doubt feel they have the right to be concerned about the children. Whilst it would be very difficult for your former spouse to stop your children meeting your new partner, you may want to think about trying to agree how and when it happens with your former spouse – or at least keep them updated about it. Otherwise, you may have exactly the same problem, but in reverse, if your former spouse wants to introduce the children to any new partner they have in the future.