Both parents should be there to talk to the child and they can’t get angry. Whatever differences they have they must put aside for the good of their child.
This is not about the parents anymore since the decision has been made to split up; it’s all about the kids. The parents have to let the child know that it has nothing to do with them.
That they did not cause it and that they are still very much loved by each parent. The children will have questions and depending on the age of the children.
The questions will vary. You have to be prepared to be honest and speak with one voice on everything that they ask. Blame does not matter at this moment.
You children are losing the full time access to one of their parents and that can be devastating to them. Their lives are going to change and they are scared.
Some of the questions you may face are
1) Who will I live with?
2) Will I have to move?
a. What about my friends?
b. Do I have to change schools?
3) What did I do wrong?
4) What can I do to fix it?
5) Why are you doing this?
6) Don’t you still love me?
This is the most important answer you will give to your child. The parents are out of love for each other and the child may think it means he or she is going to lose that love as well. You must assure them this is not the case and you will always be there for them.
One thing you shouldn’t do is bash the other parent around your children. No matter how you feel about your now estranged partner, it is not the child who must bear your burden. In fact you have to bear yours as well as theirs. You may despise your ex at this point, but in front of the children; you have to be civil and polite to them. The child is the blameless victim in all this and you both have to be careful not to cause irreparable harm to an already weakened child.