"I'm from No.11 High School."
Chen Yuan mentioned his school very naturally.
Otherwise?
Who would be secretive about their high school when asked?
Only someone with something to hide!
Sneaking into another school to flirt with young girls!
Moreover, No.11 High School is also part of the Provincial Experimental Great Perfection, a highly reputable school. There's nothing to be shy about speaking up. As a student of No.11 High School, one should be proud of their alma mater, and earn five mao by deleting the parentheses.
"Oh, No.11 High School, huh? That's very close to No.4 High School."
In fact, when Aunt asked this question, she was probing, trying to see if he had any hesitation in his mind.
If he hesitated, it would confirm that the person she saw behind No.4 High School that day was indeed Xinyu with Chen Yuan.
If he didn't hesitate, it meant he was quite firm.