Q: My husband and I are separated. One son lives with me, one with him. Our friends, whom we considered the other half of our family, picked him and cut off communication with me.

Am I wrong to think them terribly rude when they took the rest of my family out to celebrate my son’s birthday and excluded me? Am I petty in thinking that events that are for the family should include me, the mother?

My husband invited my son over for dinner with these friends but excluded me again, and I’m hurt.

A: It’s not uncommon to celebrate separately after separation — most people do. That’s not necessarily bad ex-etiquette. What is bad ex-etiquette is when friends take sides after the break-up.

Granted, there may be times when there has been blatant wrongdoing and in those cases taking sides is understandable, but as you describe it, your family friends just chose your ex and left you high and dry. We all know there may be more to the story — but sometimes there’s not.

When faced with a friend’s break-up, many just don’t know how to handle it. Some feel they must take sides, some disappear altogether. If these friends were his prior to the marriage and you became close as a result, although hurtful, it’s not surprising that they chose their old friend. The pity is that they felt they had to choose at all.

As much as we support your desire to continue to celebrate as a family, celebrating with an ex is not for everyone. We never suggest that divorced or separated parents celebrate together until they are ready.

In your case, you’re just recently separated. This is the time that emotions run the highest — and the kids are watching. What you do now sets precedent for how quickly your kids adjust and how secure they feel after divorce.

You asked if you should be offended if the events of the family did not include you. Although we do understand why you are offended, it’s time to accept that your family structure is changing because of your break-up.

That means that for the time being, two of everything — two birthdays, two Thanksgivings, two Christmases. You have even separated your children so that one lives with you and one lives with your ex.

Very little will be the same, including how you interact with old friends. When you can relax and not be “hurt” by everything your ex does and says, that’s when you might consider celebrating together. Not before.

Even the most equitable of break-ups start out rocky. For the time being, it’s obvious that your ex wants to approach your break-up more conventionally — keeping things separate. Based on that, he’s doing exactly what he should do. He’s establishing clear boundaries after the break-up.

Unfortunately, it sounds as if he’s also cutting off communication, and that’s not good ex-etiquette, nor is it good co-parenting. Time for a calm heart-to-heart in a public place — no alcohol — so that each of you understands what you can expect in the future.

All the rules of good ex-etiquette can be found on the Bonus Families website. Key word: ten rules.

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). Reach them at:

eebonusfamilies.com