Q: My ex was a stay-at-home mom and rarely went out. We break up and all of a sudden she's partying and not coming home until late. My kids, age 15 and 16, complain that their mother is never home and I'm wondering if I should file for full custody. What's good ex-etiquette?

A: You can go back to court anytime you want, but before you do, let's look at some of the reasons someone might be granted sole custody of their children:

First, abandonment — the other parent has not been around, and once served to appear in court, does not fight the motion.

Second, the noncustodial parent is in prison or another facility that prevents interaction with the kids.

Third, a mental illness that causes a pattern of poor decisionmaking.

Fourth, abuse or domestic violence against the other parent or children.

Fifth, documented drug or alcohol abuse.

You can see the pattern. If the children are not safe, then there's a good chance the court may intervene, but there has to be proof that the kids are in danger. Police reports, CPS intervention, school intervention.

What you report sounds more like a parenting disagreement — in this case, it seems as if Mom is having trouble making the transition from married to single. Going a little crazy after a breakup is not uncommon. To complicate things even more, your kids are teenagers. Most teens don't have a problem being left alone — so if they really are complaining, there may be something more going on here.

From an ex-etiquette standpoint, if we are operating from the premise that children do best when they have time with both parents, rather than file for custody, start by looking for creative ways to approach Mom that might reinforce a more positive environment when the kids are with her. Think this approach is coddling the ex? After all, she's the one who is running around. Since it's doubtful the courts will intervene, arguing will get you nowhere, especially if you're calling attention to something you feel Mom's doing wrong and she doesn't agree.

So, offer solutions.

For example, if she's going out when the kids are scheduled to be with her, initiate a first option for child care. Although it's debatable how much child care you need for 15- and 16-year-olds, saying something like, "The kids are telling me that they don't like to stay alone at night. If you want to go out when they're with you, feel free to send them to my house." It's all in the way you suggest the solution. If she feels you're finding fault or possibly recording when she's gone, it's doubtful this approach will work. You need to build trust. If she trusts you, that's when she'll ask for help. (Ex-etiquette for Parents rule No. 2.) If she doesn't, everything will be a secret. The more transparent you can both be, the less likely you will have co-parenting disagreements.

The bottom line is, it's not you against her, it's both of you for the kids. That's good ex-etiquette.

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