Once on a high-speed train, he sat by the window.

After taking his seat, a middle-aged man sat next to him.
They didn't exchange any words.
After the train started, because it was first class, the attendant distributed snacks and water to each passenger.
When it was his row's turn, the uncle sitting next to him directly said they didn't need anything.
His heart skipped a beat when he heard that.
The uncle's behavior made it seem like they were together.