Ellbell, yes, I think that's the case wrt parents talking to each other.
I remember when I was at junior school, there were two children who were particularly bright wrt maths. It was a two-form entry school, and there was one in each class. One afternoon, the teachers of those classes (who fancied each other - yuck) played their "pet" off against the other - with the rest of their class watching.
Lots of nudgey comments between them and kind of knowing winks - mine's cleverer than yours, but it all meant "and I'm better than you" as well.
I have rarely been more uncomfortable in a lesson - it was a show put on by two adults who ought to have known better.
But then, one of these teachers used to make me set, give and mark spellings to "the slower children" (her words) when I was eight, so professionalism wasn't to be expected, really.