See Lenore Skenazy’s Reason article with that title:

A mom took to TikTok, begging for advice: “My kid was outside, another kid was walking outside somewhere, and then they stopped and started playing together.”

She was baffled.

The mom went on to explain that the unknown kid was 8 years old. He was polite and seemed well cared for. He came into the house with her son, and they proceeded to play video games all afternoon. The polite, nameless boy didn’t leave for six and a half hours.

That was the issue.