Why raise the donk?

I read the HH wrong. I thought you were the one who bet and he raised. The principles still the same, if you raise him you ISO yourself vs. a stronger range instead of letting him keep his bluffs.

Villain's donk bet is pot sized. I don't see how you can raise on a board that is this coordinated. Just call and see what he does on the turn.

On a coordinated board like this, I call. On an uncoordinated board I might be more inclined to raise. Especially if his donk bet was smaller, say 1/4 or 1/3 pot. But 1/2 pot and larger I like to call a lot to keep villain's bluffs in. It depends on stack sizes, SPR, how aggressive villain is etc.

When he re raises me I just do see how he has any bluffs especially
with the pot donk. I feel like he's flush draws just flat my raise

This is mostly true. Don't assume 100% of the time this is true or you will be too exploitable and lose a lot of value with strong hands like this. There are aggressive players that will make plays like this, especially if they know you fold a lot to any type of pressure. This is why you call. It is harder to be out played when you just call. And when you are beat, sometimes you will improve on the turn, if you see one.

Think of it this way, villain could have a pair, a gutshot and a flush draw on this board, all at the same time (Q9s and T9s). If so, he has a mountain of equity. If you add in fold equity with his aggressive betting/raising, you can see villain doesn't have to have a nut hand to play this way. AQs has an over card, a gutshot and the nut flush draw, etc.etc Lot's of hands have lots of equity on this board but do not currently have you beat. Fold equity against tight players makes this a more profitable line for the villain than just calling to hit his draw.

Folding is bad because even if you only continue on the turn with a K or J you are getting good enough odds to try to hit your 4 outer because you'll stack him every time in position with this much money going in on the flop unless he's somehow just on complete air. I feel like your fold smells a little bit of scared money not wanting to make tough decisions for a stack on the turn.

I think your raise on the flop is fine. You're hardly ever getting 3 bet here and I feel like people saying you put yourself in a bad situation are being results oriented because 95% of the time people are just calling here with a draw or folding whatever crap they decided to donk with. That said, I agree with tr33f1ddy that you should go bigger on a board this dynamic. Bad situations are inevitable in poker and it's how we become better, which is most of the point of 5 NL.

When the 3 bet is this small I'll probably see a turn but I'm not really feeling a fold here except on bad turns (of which there are plenty). A normal sized 3 bet I probably just say screw it and get it in because he could have a few worse value hands and a crap ton of draws. I mean if we give him 19 combos of QT and 99 that means he also has the unsuited KJ, J9, and K9 (16 combos). And any heart + gut shot might play like this or heart + pair, pair + gut, or whatever.

If he plays this aggressively with his value hands then we know we actually beat a good chunk of them on the flop. He might have 99 and might have QT but its very unlikely that he has KK or JJ and we beat K9 and J9. So with 19 combos of hands that we lose to, 15 combos that we beat, even if he has no bluffs in his range we are getting very good odds. The problem is that when we flat, we are very likely facing a turn and maybe a river bet while playing a very big pot with a lot of bad turns and rivers for us. A 7, Q, or any heart is gonna suck. But if we fold KJ then what is our continuing range looking like? If we had a heart draw it would be very difficult to fold here as we're pretty much getting direct odds, especially with the nut draw. But we can't ONLY call or raise with heart draws because it's too exploitable, either our opponent always folds when a heart hits or always blasts when it doesnt and suddenly we lose all our value.

So our question becomes "do we ever shove on his raise?". Conventional thinking is no because we'll isolate ourselves against his strongest hands and get all of his weaker hands to fold. But if that's the case then we definitely want a raising range here (if he's playing aggressively with 2 pair+ AND we think he'll fold the weaker part of that then we're losing a ton of value by not having a bluffing range), we just want it to be polarized with strong hands and draws, and KJ isn't strong enough, so do we call then? We need to find a way to differentiate between which hands we'll call with and which hands we'll raise. So if we raise straights and KK, call other sets and some 2 pair, it will really help balance out the draws that we're calling with (remember we cannot fold some of those draw because of the odds we're getting, literally almost direct odds to hit on the TURN).

Honestly I might just fold J9 here because it makes it harder for him to have QJ, but KJ is way too strong to fold in my opinion. I mean I can't imagine this guy is really thinking about how his sizing is letting us call profitably with more hands. If we see him do this more and he keeps showing down the nuts then we can adjust our strategy to only flatting with those draws that are getting the right odds to draw out on his hands. But remember, a heart sucks but it won't always be terrible, he can be afraid of it too. Right, like if we think a heart always gives him the winner then we just jam flop and hi five everybody in the room.