re: Poker & PLOH: Flopped nut flush but turn paired the board
It's one of those ones where your play was pretty solid, and folding may well have been the right choice. It depends on the player, though - if he's the kind that would play a non-nut hand, then I'd have been inclined to call, but it is tough.
It's purely a judgement call, at that point - it could easily have been a semi-bluff with trip kings, which would have left you in reasonable shape, you'll never know.
Getting off a big hand isn't easy, though, and even if it was the wrong choice, it's a good skill to have.