Ex-etiquette: Birthday shopping for a partner's ex? Lead with love

Q. My partner has a very cordial relationship with her ex. They adopted a child together and share custody now, so I am with their son quite often. I have had a strained relationship with my partner's ex, and something has come up recently that has really thrown me. My partner travels for work and has very little down time. She will not be able to buy a birthday present for their son's mother, so she has asked me to take their son out to buy the present. This just sounds weird to me and makes me really uncomfortable. What's good ex-etiquette?A. The first time I took my bonus kids to buy a present for their mother was quite an eye opener. Their dad left it for the last minute, which was typical. I thought he was crazy to ask me to do it and told him so. He didn't care. He just needed my help. So reluctantly, I loaded the kids in the car, and we headed for the mall. During the drive I did my best to cover up how irritated I was being in this position. Buying a present for my husband's ex? Was I crazy?When you buy a present for someone, you must consider what they like. I didn't know, so I had to consult the kids. I watched their happy faces as they talked about their mom. When they started telling me funny stories about the things she did, through their giggles, that's when everything sunk in. It wasn't me against her — it was all of us for the kids we all loved. I had just wasted a lot of time acting foolishly.As the kids and I considered this or that for their mother's present, my then-9-year-old bonus daughter squealed, "This is so fun!" I can still hear her voice — and that was the shift. Rather than feel jealousy or anger, the act I had been dreading instantly became a privilege. Buying a present for her mother made a child I loved happy.From then on, each year I took the kids out to buy a present for their mother. Sometimes their dad went. Sometimes he didn't. But the gesture of openly considering what their mother might like brought us all closer. Although we never discussed it, it brought their mom and I closer, too. She knew her ex and knew who was buying the presents. It changed her attitude toward me as well.My kids have taught me many things, the most important being to lead with love. They didn't know about the trials their mom and I struggled with; they just knew they loved their mom. I realized firsthand, we — all the parents who took care of them — were teaching them how to be in a relationship and how to solve conflict gracefully. All the adults in a parental role were their role models, and that included me. We all had to set the example. That's good ex-etiquette.