When we agreed to host Jerry, a 12-year-old boy from Shanghai, we looked forward to being his guide to local sights, food and attitudes.

But we had a secret reason too. We knew the learning would be two-way. Just as Jerry would get a taste of American life, our two girls - Zoe, 6, and Maya, 4 - would gain a window into his world.

There was a third experiment we hadn't expected: sibling dynamics.

Jerry was great with the girls. He helped Zoe with her Chinese homework and played Legos with Maya.

But he was also a 12-year-old boy. He learned that little sisters can be highly volatile. An only child, he clearly wasn't used to so much drama in his day.

One minute, they'd be laughing hysterically together, hunched over a made-up board game Jerry created with a piece of paper and a marker. The next minute, they'd come to us crying because Jerry had done something - poked them with a twig or something as he pretended to sword-fight.

More than once, we found Jerry sitting, head in his hands to drown out the wails around him. He was mumbling to himself in Chinese, something to the effect of: "Cry again. So annoying."

We tried to get him together with other boys when we could. He certainly had fun with William, our 9-year-old nephew, when we all went up to a resort near Ely in northern Minnesota. They swam and kayaked together and explored the woods, climbing rocks and hiking.

All too soon, three weeks had gone by. We know it was too soon because Jerry told us so. "Why, why, why do I have to go home?" he wanted to know. "Why can't I stay one more week?"

On Jerry's final evening at our home, I asked him to list his most enjoyable moments in Minnesota.

No. 1 was easy: Ely.

Then it got tough. He scratched his head and deliberated. Not because he couldn't think of other good times but because there were too many.

No. 2: Mall of America.

No. 3: the Twins Game Chris took him to.

No. 4: "every lake I ever swam in."

No. 5: everything about the 4th of July - parade, fireworks, a friend's barbecue party.

No. 6: the free neighborhood puppet show we watched in someone's back yard.

Jerry's list made us happy. And then he was gone, off on a plane and out of our lives again.

Goodbye, Jerry. We'll meet again.