Q: My ex and I were married for six years and are getting a divorce. We have two children, 3 and 5. He left because he met someone else and she and her 3-year-old daughter spend every weekend at his house even on his designated weekends with our kids. How can I get him to realize that he needs to spend some time with just our kids?

We get along well and I have talked to him about this, but he doesn't seem to understand how important it is. What's good ex-etiquette?

A: To begin, I am sorry. Breaking up is hard. Breaking up, under those circumstances, is awful. Unfortunately, there are a few red flags that need to be discussed.

• First red flag: "How can I get ... " The answer lies in the adage "You can lead a horse to water, but you can't make him drink." In other words, you can't "get" anyone to do anything. You can't nag him into being a better parent — it will backfire and he won't want to talk to you.

• Second red flag: How do you know he's not spending time with the kids? Is it because two very young children told you so (doubtful) or is it because you know she's there on the weekends and you're anticipating that means he's not spending time with the kids?

• Third red flag: Why does he only see his kids every other weekend? That's 10 days between visits. Aside from you thinking he doesn't spend enough one-on-one time with them when he sees them, why does your parenting plan only designate four days a month for the kids to see their dad? Of course, there may be extenuating circumstances. I get that he left for another woman, and that comes along with a whole other set of problems. He may also live too far away for midweek visits. He could work off hours, but all things equal, if he saw them more often than every other weekend, this problem may not be a problem.

Of course, I'm reading between the lines here, but it sounds like you were the primary caregiver when you were together and now that Dad's gone, he's left to his own parenting devices. You don't trust he's doing it right — I mean look what he did — and therefore you must run defense or the kids will be hurt further.

Here's something that may or may not make you feel better. Many noncustodial parents have confessed that they became much better parents once they divorced because it was up to them — and only them — to step up. The best thing you can do at this point is to look for ways to cultivate a positive co-parenting relationship where he feels comfortable asking for help if he needs it. It won't be easy — the hurt is still pretty raw — but tell yourself you aren't doing it to make his life easier, you're doing it for your kids.

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