[ipokeder]

i think flop check is fine since the pot is protected, it's not really a good idea to try to build a huge pot and play it all in, plus checking the flop adds an element of deception and doesn't turn our hand face up, which is good for getting paid off by worse hands - betting flop pretty much means we want to get it AI by the river and in that case we'll usually get it in bad by then, whereas by checking the flop we get paid off turn/river bets by a lot of worse hands. considering you coldcalled a huge 3-bet, any decent player will be able to fold all worse hands to a flop bet. i mean, this is all assuming he's a competent player, which is pretty integral to the hand.

if he's a fish then bet the flop and get it in there