Well everyone checked through the flop and utg+1 bets less than half the pot on the turn, I would think you have a ton of fold equity here. I'm usually betting that flop when it's checked to me as well, it's probably not the right play though.

I don't think you are going to bust anyone if your draw hits to be honest though. Nobody has shown any strength and I don't see why they would go crazy and pay you off if you river the nuts. So you have about zero implied odds for calling.

Then again you aren't repping much and there isn't much reason for an ace high flush draw or any flush draw with over cards to fold here. Unless you limp call with 99. Of course I'm over thinking and I'm sure the villain doesn't even remember preflop action at this point.