Co-authored by Dr. Peter L. Stavinoha, co-author of Stress-Free Discipline
As difficult as separation or divorce is on parents, we all know it can be even more difficult for our children. However, you can set the stage for your child's longer term adjustment to this life event. Here are some tips for having that talk, the one where you break the news:
•Before you sit down with the kids, get your own feelings and thoughts on the same page as much as possible. While tensions may be high, both you and your soon-to-be-ex will need to be civil co-parents. Why not start now? Waayyyy easier said than done, we know, but try to plan out how you're going to break the news to the kids, keeping their feelings as your priority, and showing mutual respect for each other. It won't eliminate the difficult ramifications of their family unit splitting up, but it will certainly soften the blow and make it easier for them to bounce back from the devastation. Discuss what will be said, who says what, and what each of you feel should be off-limits in the conversation. If you cannot sit down together, it will still be helpful for you to consider these issues before the talk.
•During the talk, try hard to keep your own emotions in check. We realize this is agonizingly hard, and we're not advising you to be completely unemotional. 
But falling to pieces in front of your children will make them feel even more unstable and anxious. They won't be able to focus on your words, and neither will you. Pinch yourself during the conversation if you need to. Keep in the very forefront of your mind that this talk is all about your children, and how they are going to be able to handle this news; it's not about you. Consider taking a day, or two, to let the circumstances sink in and then sit down together for another talk. If your ex won't participate, you can do this follow-up on your own.
•Break the news at home and not out at a restaurant or another location where they may feel uncomfortable showing their feelings. Choose a public part of the home: the kitchen, the living room, any general space is an okay choice, as long as there is room to sit down and be comfortable. They may have a lot of questions, so choose a place you can stay for a period of time. Also, it's a good idea to not tell them in their bedroom, which is their safe place. It's very likely they will replay the talk over and over in their minds for a long time, and so the setting should not be the place where they are likely going to process the news.
•Maintain a sense of unity by telling your children at the same time. Gather them together for a family meeting. It may be hard if you have multiple children with multiple activities, but it's really essential that this conversation happen with the whole family. Siblings may find this situation to be one that bonds them together, if not right away then down the line. If you have older children who either aren't living at home or simply unavailable, try to break the news to them first and then tell the younger ones.
•Build in some time for your kids to prepare for the separation, but not so much that they can stew over it or start to think it won't happen. This is especially true for younger children who may be confused if a divorce is announced and then nothing seems to change. Involve them, to the extent possible, in the choosing of some of the aspects of a new place to live, whether it's the place itself, or the furniture arrangement. If one of you has already secured a new home, then wait until it feels okay to steer the conversation in that direction and then let them know. Having those concrete plans, or making a plan together, can reinforce their sense of security and dispel some of their anxiety.
•Don't hem-and-haw trying to find a way to break it to them gently. Your words cannot be ambiguous; they must be direct and honest. Your children need to know and understand what you're telling them. Reassure them that both you and your soon-to-be-ex will love them, always, and that nothing could ever change that. They need to have their questions answered, even those that may seem inconsequential to you. If you don't know an answer, let them know that you'll figure it out together.
•Explain that it's not their fault. If they've recently been in trouble, you may need to make sure they don't connect the two events. Understand that even older children can be scared and blame themselves. They may not let you know this is what they are thinking, but it is human nature to want to find a cause - and therefore a potential fix - to a problem, and so most children do tend to think their behavior is the cause of a divorce. You and your partner need to expect these feelings, understand where they're coming from and be proactive in dealing with them.
The separation or divorce talk can be one of the most stressful for both parent and child, but some planning and civility can go far in giving your children a sense of security during this time period.