i don't like checking the flop - If they have an ace you will find out w/out losing too much - However, if they are in there with a KQs kind of hand and you check 2x all of a sudden they might be thinking 2nd pair is good - How many times do you NOT bet in a 3 way pot when checked to twice? I would bet there with 2nd pair or any kind of draw - But if you lead the flop they may fold weak aces since your repping good strength -

Since you checked twice, I would prefer you check/fold the turn bet instead of check/calling...This, IMO, is definitely where the "calling is weak" comes into play - you either want to bet or fold -

don't get too down on yourself though - its only 1 hand