Tales from the school yard.

Aside from the mundane sexism of not caring what the mothers did (which isn't what makes the story stand out), I can only assume you've missed the point that the kids didn't know what their fathers did because they didn't know who their fathers were.

And there's nothing bad about that, but society (still) often thinks there is and the teacher humiliated a kid, reducing him to tears, and then repeated the mistake because insensitive idiot.

In fact, we all knew their situation and I never saw any of the other kids use it against them, which made a class of 11-year olds more sensitive than the teacher.