Q: I came home from work early and found my ex and our 10-year-old son in my house. They were sitting in his room talking, but I think it was wrong that she was there.

We have not been together for two years, and our son spends a week with me and a week with her. She does not have a key, it's not even a house we have lived in together, but there she was, comfortably lying on our son's bed talking about his day.

How do I handle this?

A: You're in a difficult situation. The boundaries appear to be a little blurry, and a conversation with the ex is required. Notice I didn't mention talking to your son at this point. It's difficult to say, "Son, don't let your mom in the house," particularly if you and Mom have been cordial when co-parenting. That puts him in the position of monitoring Mom.

Two years is not that long after a breakup, and sometimes parents have a hard time severing ties.

If you two get along, your son may not understand where boundaries stop and start. Mom drops him off from school on your week, no one is home for a few minutes, and it becomes, "Why don't you come in, Mommy?" Mom figures, "What the heck?" and you come home to the ex and your son cuddled on the bed, talking about the day. But what if you had a new friend with you? What if you had a headache and didn't want to deal with all this? What if you just plain want your privacy? You have to be clear:

1. Do not come into my home for any reason when I am not there.

2. If you would like to pick up our son when it's not your week, make arrangements with me, not our son.

3. Verify that after-school child care is in place and there's no question who will be watching your son on your designated time.

It's also important to make sure you have not confused your son. Too much joking or even a casual goodbye hug that lasts just a little too long can give a child false hope of reconciliation. He may seem fine now, but once he realizes there's no reunion in the works, you could once again be faced with a child dealing with Mom and Dad's breakup. Facing that one time is bad enough. Facing it twice can be devastating.

Finally, Mom could know full-well what's she's doing. Make sure she knows no reconciliation is in the works, as well. Have that conversation with her as soon as possible.