"I’ll race you to the park," said the teenager, rolling his skate board on the sidewalk. "last one there buys the ice cream!"

The little girl nodded and started pedaling her tricycle, steady and slow.

The teenager zoomed ahead — but halfway there, he spotted the ice cream truck and stopped to buy a cone for himself.

By the time he reached the park, dripping ice cream in the sun, the little girl was already at the playground, waiting with her hands on her hips.

"You owe me a cone," she said.