Q: My ex-husband's girlfriend of less than three months has told our two sons that she is going to have a friend of hers take a picture of the three of them as a present for their dad's birthday. I did not say anything when my son told me, but I came unglued on my ex. Now he won't talk to me, and the photo shoot is coming up. What's good ex-etiquette?

A: The fact that your ex's girlfriend is taking such an active role in your kids' lives in such a short time probably seems quite inappropriate to you.

This is understandable — and it is commendable that you didn't respond in anger when your child told you of the plan, but losing it with your ex isn't helpful either. The more aggressive you are, the less likely he will take your concerns seriously. It would have been better to ask about the plan and listen to his thoughts before making your thoughts known. Losing your temper gets you very little when negotiating with an ex.

Relying on the "10 rules of good ex-etiquette for parents" can be very helpful when dealing with this sort of problem, specifically, in this case, Rule No. 9, "Respect Each Other's Turf." This means you can't control what goes on at your ex's home and that includes picture taking with the new girlfriend, but the picture will be viewed at your ex's home and it's part of his life with his sons.

Attempting to control life at the ex's house will alienate him and fill you with anxiety when you realize you are up against a brick wall. Although many divorced parents might scoff at this next statement, cultivating respect and learning to trust that your child's parent will make their decisions in the best interest of your children is key to successful coparenting.

Before jumping to conclusions, check with your ex to find out if this girlfriend is as serious as it sounds. If she is, then it's time for a heart-to-heart to discuss how he sees her in the big picture and make a plan for how you will all interact. The biggest drawback in all this is that the kids are party to the growing pains. At this early juncture, a picture of just the boys might be the best way to proceed.

You never know, this whole thing could backfire. Presenting your ex with a picture of the kids with her could alert him to how serious she is, and that may not be what he wants after only three months. It could slow the whole process down. Or, it could solidify their commitment, and you will have a whole new set of problems to face. Either way, there will be bigger problems than pictures with the girlfriend to face in your efforts to coparent after a breakup. Use solving this problem as the groundwork for solving the bigger problems in the future.

Jann Blackstone is the author of "Ex-etiquette for Parents: Good Behavior After Divorce or Separation" and the founder of Bonus Families (www.bonusfamilies.com).