Shuttling between parents, boy acts out

DEAR AMY: I have a 4-year-old son. His mother and I have lived apart for 18 months. He spends time equally between the two of us. For the past few months, he has demonstrated a strong preference for me over his mother. When I drop him off at their home he throws a huge fit, wanting to come home with me. He has also begun saying that he doesn't love his mom -- he only loves Dad. He has even thrown a fit when she picks him up from day care, saying he wants Dad to pick him. I have tried talking to him but it's not easy to explain that he can love both Mom and Dad when he's so young. I never speak ill of her to him and I even tell him how much Mommy loves him but his response is always, "I love Dad." I don't think I am doing anything to promote his behavior. Any ideas on what would cause him to act/think this way -- or how I can alter it? I know it's upsetting for his mom to hear this, but it seems that it's progressing.

--Concerned Dad

DEAR DAD: Let's stipulate that there are no serious issues in the mother's home. If that is true, I would say you might be unwittingly promoting this behavior when you respond to a tantrum by talking with him about whom he loves.

It's possible that this is not about his mom. He might be working extra hard to ingratiate himself to you because he's afraid you'll drift away. He needs to know that you are always going to be right where he left you. Reassure him.

The way to help him make transitions is to give him the most predictable and calm environment and to encourage him to behave appropriately.

You and his mother should deal with this consistently. Make sure there isn't anything going on at her house to make him anxious. When he freaks out, calmly comfort and reassure him. Say, "Buddy, you're going to be fine. I've got to go but I'll see you tomorrow. Let's say a nice hello to Mommy and I'll see you later."