Q: My ex-husband and I live quite close to each other for the sake of the kids. I have been in a very serious relationship with a man for the last year and he has recently moved in with me. My son just came home and said that his father’s girlfriend’s daughter, who is in college, had a boy spend the night with her while my son was at his dad’s house. I think this is inappropriate and told my ex as much. At first he told me to mind my own business, but now he won’t even answer my calls. I’ve texted him as well. Nothing. When we were married, our children weren’t allowed to go to certain homes that we felt were not safe or did not agree with our moral standard. Now his home has become one of these homes! What is good ex-etiquette?

A: I see a double standard here — and it sounds like so does your ex — that may be why he’s not answering your calls. Both of you are living with people in the presence of your children; however, you are offended by his girlfriend’s adult daughter doing something similar. Perhaps it’s the casualness of her hook-up that bothers you. You perceive you are in a serious relationship, but she is not. Truth is, you haven’t given me enough info in that regard. She may be very serious — and it would be interesting if that would make a difference in your perception. You also haven’t mentioned the age of your son, but, bottom line, it sounds to me as if this is a “do what I say, not as I do” sort of proposition.

Many make the mistake of thinking that since they parented one way when they were married, that’s what they will do now that they are divorced — and ideally, that would be great, but more often what happens is while married, one parent was more dominant, and in order to prevent arguments the other just went along. Once divorced, the less dominant parent starts making decisions that coincide with his or her own beliefs — and the previously more dominant parent doesn’t understand the big change. Unfortunately, there is no big change, just really bad communication while married.

I suggest you consider ex-etiquette rule No. 9 — Respect each other’s turf. You can only control your own four walls and you have to trust your ex to control his. Your ex most likely knows how you feel, and he’s made the value judgment that’s it’s OK at his house. Have to say, though, your actions say you agree, so I understand the confusion if you are telling him it’s inappropriate when someone else does it. Since you are also living with someone, he probably wasn’t expecting a negative reaction and feels it’s hypocritical to say anything.

Finally, you can’t dictate policy via text message. Set aside a specific time for discussion and hash things out in person. If you are concerned what all this is saying to your son, stop doing it.

Dr. 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. Reach her at:

drjannblackstone@gmail.com