Would no one go for a check-raise on the flop? Betting out gives everyone 11:1 to call. Chances are you are ahead, but you are vulnerable to at least 4 overcards and spades on the turn, so isn't it worth the risk of having it checked through?

Must call the turn reraise with 7.5:1 and 9 clean flush outs + the 9's

River may be difficult to let go, but there are two players behind you yet to act and any 4 beats you. Wouldn't be surprised to see 33 either.