Q: Huge dilemma! Yesterday morning I was having a conversation with my sister, and my 11-year-old stepdaughter overheard the conversation, about which she then proceeded to tell her mother. One of the things I said was that her mother was selfish and projecting her feelings about their dad onto them -- and that's not fair, etc. I don't know what to do! My husband's ex called him immediately ... help?

A: Now you see why we added ex-etiquette rule No. 3, no badmouthing, and we were careful not to specify who should not badmouth for this very reason.

You badmouth anyone when the kids are within ear shot and you have set yourself up for failure. They will either personalize it (they know they all share DNA -- in other words, say something bad about Mom and you're saying something bad about me.)

There's also a chance that the child, feeling wounded and protective of the badmouthed parent, may identify with the underdog and reject the one who is badmouthing, no matter who it is: Mom, Dad or you.

Any way you look at it, badmouthing, on any level, is just not a good idea. Badmouthing always backfires.

Granted, if you are angry, it's human nature to want to vent, and a sister is a great audience. But when the kids are in the house, it's just too easy to think they are watching TV and they're really just on the other side of the door, listening to every word.

And, since they can then only hear one side of the conversation, they have to fill in the blanks using their child intellect and experience. So your husband's ex was basically told about a one-sided conversation, edited by 11-year-old, which an adult had to then reconstruct, and that's what she reported to your husband. It's a wonder what got back to her was reported with any accuracy at all.

What do you do? You talk to your husband about the situation, get on the same page, and then you eat a very large helping of humble pie when you call mom to apologize.

You tell her the truth, you were angry. You did not take into consideration that her daughter was listening and that was wrong. You are embarrassed, you used poor judgment, and you are very sorry it has come to this. At that point, you may want to use the situation to discuss whatever was bothering you in order to clear the air, or simply hope she accepts your apology and just leave it alone.

But, it starts with you accepting responsibility. And you do this not only to clear the air, but also to set an example for your stepdaughter.

Ex Etiquette rule No. 1, put the children first, means in every decision, even when you have to clean up a mess. And, next time you want to vent, meet your sister somewhere for coffee.

Jann Blackstone-Ford and her husband's ex-wife, Sharyl Jupe, authors of "Ex-Etiquette for Parents," are the founders of Bonus Families (www.bonusfamilies.com).