[JJNJustin]

The three bet preflop is iffy. I could play it either way, just calling or three betting. The problem with three betting with A9 is that you are basically telling him you hold an ACE, and also showing some hostility because he is going after you blind so aggressively. Had you just called his raise, he would have no idea what you held, and you, having position, would force him to check alot, either on the flop or after, to see if it missed you or not. Also, by three betting, as you see by your own play, you get sucked in to the hand and have a hard time getting away from it (you kind of tried to hit a runner runner flush here). Lastly, you give him an opportunity to make it 4 bets if he indeed holds the best hand, whereas had you just called he would have no such opportunity.

Say for example he holds Ace with a better kicker something huge like AA, by calling with your A9s, you are getting 3 to 1 immediate pot odds and implied odds if you catch a flop. A9s is about a 3 to 1 underdog to AK, so you are still playing correctly. Now say you 3-bet and he caps, now you are putting in 3 bets to win 5 + implied odds, so you are getting much the worst of it here. However, if he holds a hand you beat (like KQ), he is still only a small underdog to your hand (A9s), and if you 3-bet him his is not incorrect to call your raise, since he raised to begin with.

But, having said all that, there ares still some instances where I would 3-bet. Against a weak player, a tight player, or someone who would go after my blind with anything. Most often, though I would just call. Had your kicker been in the face care region, I would lean towards re-raising, but as I said before, I could play it either way.

The flop misses you completely. He bets, which could mean he has a pair, some kind of straight draw, Ace high, or nothing. With this flop, it is more likely you are beaten than if three rags flopped. Also, remember even if you do hold the best hand with Ace high, you are not that much of a favorite against many hands because of the straight draw. For example you are in bad shape against any K, Q, and horrible shape against any AK, AQ, AJ, or AT. Even against JT, J9, 98, T8, T9 you are either 50/50 or he may be a small favorite. Against any pocket pair you are in bad shape. The only hands you are really beating here is A8 and lower, and he has a good chance to chop with you.
So all this being said, the flop is bad for you and you should strongly consider folding. If you feel he is weak you might raise him once, but if he calls dont bet anymore.
I would probably just flat fold here. By not three betting before the flop, I can get away from this hand on this bad flop more easily.

I would say that is your only real mistake is just calling on the flop. You either want to raise and hope he has nothing and folds or fold yourself, because the flop has missed you.

best of luck
-J