[Ghazban]

I dislike the flop check. A benefit of not raising preflop is that, when you get a flop like this, nobody will put you on top set. Bet out and hope you get raised so you can get all-in on the turn. The straights that kill you with this turn card should not call a flop bet. Had you raised preflop, you might have reason to check this flop in the hope somebody puts you on KK/QQ/etc. and represents the ace by betting.

On the turn, what do you put CO on that's good enough to come over the top of both a bet and raise in front of him? I won't say you need to fold (you've got the 3rd nuts and a redraw to beat the first and second nuts) but you can't rule out the two hands that beat you due to the lack of betting/raising prior to this point in the hand.