Q: My kids' father and I do a good job of co-parenting, but he does one thing that really bugs me — he never returns the kids' clothes. I ask him for them and he tells me I'm nuts. His house is a black hole. I've gotten to the point that I make them change before they go to his home. What's good ex-etiquette?

A: Certainly, not asking your child to strip before he or she walks out the door. This is not about "clothes," this is about you and Dad — and it's time to make some changes.

The two complaints I hear the most from parents attempting to co-parent is "He (or she) is always late!" or, "He (or she) does not return clothes!" Ironically, they're both symptoms of the same problem. Being late or not returning clothes are both ways to control the situation.

Some would label it "passive-aggressive." Most will tell you they don't do it on purpose. That's baloney. You know when you're late and you know you aren't returning the clothes. Both are simply ways to get at your co-parent, thinking that no one really sees it. That's really bad ex-etiquette.

Your kids are watching this dance you do with their other parent. If you're late for an exchange or you won't return clothes, the receiving parent becomes frustrated and angry. Your kids anticipate the turmoil and will eventually not want to go to the other parent's home — not necessarily because they don't want to go, but because they don't want to deal with the stress of the exchange.

This is when the parent who is on the "outs" starts blaming the "in" parent for sabotaging their life. Obviously, he or she is doing something, saying something, or buying the kids more stuff to make them not want to return. Truth is, it's the fighting, no matter how subtle, that's making your children choose.

If you and Dad really want healthy kids, you're both going to have to make a concerted effort to cooperate for the sake of your children.

Here's a personal story to drive the point home.

My bonus kids' mother and I used to send all the clothes back and forth, except my bonus son's good slacks. We both wanted "good" clothes just in case we went out somewhere with the kids. It was one of those bones of contention, "Darn! She didn't send the good pants back again!" One day my family was moving and in the closet I found a pair of size 8 boys slacks. My bonus son was 15 and 6 feet tall. I realized at that moment it was never about the slacks. It was about who controlled the kids' stuff.

It sounds like you and Dad may be going through the same thing. It's time to make a change.

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