Is this bad etiquette?

[andyfox]

In no-limit, it's cool for both players to show right away. Plus it's nice in that both players know exactly where they are from the get-go.

In limit, I always show right away when my opponent goes all in. It's a courtesy that I would like to have extended to me were I in that position (which, of course, sometimes I am).

It just comes down to the Golden Rule. If you wouldn't want to think your kings are good because the other guy didn't show his aces, then don't do it to the other guy. Some players seem to enjoy the meanness of the act as much as winning the pot.

A couple weeks ago a guy bets on the river and I call. He says "no pair" and I show my top two. He then tables his flush. I say nothing, but another player at the table says, "No pair and no class."

Exactly.h