Q: I often hear, “Set clear boundaries” when co-parenting, but my co-parent just does what he wants, and I am left frustrated and angry. For example, he’s never on time. The court order says 10 a.m. on Saturdays. He rolls in at 10:30, and I’m sitting at Starbucks for a half-hour with a crying 3-year-old. To make my point, I started to be late, too. It made no impact. What’s good ex-etiquette?

A: A boundary is a limit that you set for acceptable behavior. But, if you are wishy-washy, people don’t know what you expect. That’s where the term “blurry boundaries” comes from.

Your example of being late is a perfect illustration. It just reinforced that being late is of no consequence to you. Revenge rarely sets the example you want.

I often am asked how to set a clear boundary. First, identify your limits. Consider what actions, behaviors and situations you will accept and what you will not find acceptable.

Then, put the boundaries in place as soon as possible. Once a boundary has been breached, it is difficult to be taken seriously. Finally, be consistent. Once you’ve communicated your boundary, stick to it.

Use “I” statements to communicate your feelings. “I feel (name the emotion) when (describe the action) because (describe why). I would like (name the corrected behavior).”

The following is how putting a boundary into place looks in real life. The example follows the model above, but more importantly, the original boundary was breached and this co-parent is asking that it be respected.

“I’d like to revisit how we communicate the kids’ schedules. Our previous decision was that there was no need to send each other reminder texts once the kids’ extracurriculars were entered into the calendar. But I am still getting reminder texts from you.

“I appreciate that you were previously responsible for getting the kids to their activities, but I must ask you to respect our original agreement. Our responsibilities have been clearly defined, so let’s do our best to stick to our agreement.”

Be direct and stay calm. That’s good ex-etiquette.

Jann Blackstone is the founder of bonusfamilies.com.