Villain in this hand seems a very good hand reader and, in the 5 orbits I've been at the table, has stacked 2 different players with semi-weak holdings when they hit 2 pair or a set and couldn't lay it down to weak straights/flushes he'd make....and all of those hands he bombed the river. He's aggro all-around and that's why I just called on the button.

I'm torn on whether to vbet the river or not. I've not seen him not bet a river when he thought he was ahead, but I'm always folding the river with worse hands and shoving with better, and checking allows me to bluff and let him just call with QJ, KK, and flushes, so I have to think a smart player would know checking was the best play.

PokerStars Pot-Limit Omaha, $0.50 BB (5 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

saw flop

Hero (Button) ($48.95)
SB ($51.85)
BB ($42.75)
UTG ($108.55)
MP ($143.35)

Preflop: Hero is Button with , , ,
UTG bets $1.50, 1 fold, Hero calls $1.50, 2 folds

Flop: ($3.75) , , (2 players)
UTG bets $2.50, Hero calls $2.50

Turn: ($8.75) (2 players)
UTG bets $5.50, Hero calls $5.50

River: ($19.75) (2 players)
UTG checks, Hero bets $13...

If he's aggro, shouldn't we be looking to 3bet PF here to try to get it in if possible?

Even if not - because I can see the case for the PF flat as well - why aren't we raising the flop?

As played to the river, I think the bet was correct.

flop is meh, we just have an overpair w/tarnished outs and the 8 out NFD

BD straight too I guess

river looks good to me. The turn counterfeited QJ and he needs to show up w/a FH here to have us beat really (or 4x inducing). Our line also looks bluffy, and every draw missed, so it's not as if we can't expect to be called by worse two pair.

i like 3 bet preflop for value. if we 3 bet pre and he flats we see this flop and he donk bets it we have a ton of value in 3 betting this flop then, and probably forcing villain to dump flop a lot, we can represent a set on this flop and could force villain to fold unless he has a set, even middle set may (depending on our image) have a bit of a hard time calling. This line puts a ton of pressure on lag and most lags hate to see play back at them

I re-raise preflop - if I didn't raise preflop I would def raise the flop. I think the smooth call on the flop is horrible actually. Your hand is a pretty big favorite against his range I would think, and getting him to fold random one pair and gut shots is huge. For pretty much the same reasons, I think a good argument can be made for raising the turn as well.

Now after criticizing your play on every other street :-) I'll say that I do like the river bet.

i dont always like 3betting pre with AAxx against decent players because unless he knows we can also 3bet like JT98ds, he pretty much can peg our hand and even out of position put us in some tough spots on flops like these (well, assuming we didnt have the fd to back up our AA). we have position and can somewhat take this away by checking back some flops, though then if he's as aggro as OP says he may just pot turn and river and give us a tough decision. im not saying i would never 3bet, but it does polarize our range a lot and against decent, thinking players this can be really bad.

against random guys they probably think we have AAxx but if they dont hit the flop they just fold anyway and wont often play back at us, so it doesnt really matter.

i'm ok with the flop. yeah we have a FD but the QJx fits a lot of utg opening hands and it would suck to get 3bet with just our overpair and 8 card fd. also, if he is opening weaker hands we could be way ahead of like 5678 or worse, and theres not much harm in flatting, since he folds total air but may bet the turn with it. we can use our position if trouble cards hit the turn.

zero value in raising turn, except to fold out straight draws, but it sucks to get 3bet there more than it does on the flop.

river is a probably a good value bet, as he might call with KKxx or QJxx or even AQxx if he thinks we missed a draw. im wondering what our plan is if he raises.

I wanted to return to this hand becuase I feel pretty strongly that just calling the flop is wrong. This logic for calling is not convincing. This is a common play in no limit holdem, where we might think about flatting with AA on this flop to let villain continue to bet his TT, but it is very rarely a good play in omaha (it might make sense with top two on a K83 rainbow flop for example, but it is not that common).

The flop is so drawy that villain's range contains very few hands that are pure air. Most of the weak hands in his range have at least a board pair or a gutshot, but many of these hands will have trouble calling a flop raise. That's the main reason why it is vital to raise - to protect our hand against these holdings. If we give villain a hand like JT87 (middle pair+gutshot), it is almost impossible for him to continue against a raise, but he has something like ten outs (varies slightly depending on suits) to make the best hand on the turn plus backdoor draws. There is no way you will recover enough equity from villain double-barrelling with air than you will lose by giving someone with ten outs a chance to beat you when he would have folded to a raise.

Another major reason for raising is that we are a significant favorite against many of the hands that "hit" this flop for villain - KT9, AKT, KKT, KQT, KK with spades, T9 with spades, etc. He may decide to play fast with these hands, which would be a big mistake for him, and very profitable for us.

Another reason to raise is that there are a few made hands that have a hard time calling a raise - bottom 2 with no draws and so on. Even if he folds a better hand only a small % of the time, that's more profit for us.

Finally even if reraised and we are beat it doesn't suck that much because we still have excellent equity against 2-pair and reasonable equity against sets.

In summary, this is a raise on the flop and it is not even remotely close. Pretty much the only way a raise would not be clear is if villain's range for betting out on the flop includes only wraps+2pair or better. Even then though it would probably be at least not terrible to raise and get it in.

I'm not sure if you misread the OP, but I'm flatting the flop because I want the villain to shell the turn instead of chasing him away against a WB hand.

This is dead wrong, as explained in my long post. There are few way-behind hands in his range, but a lot of draws with 5-10 outs that he will fold to a raise. The equity you gain when he bluffs the turn with air is insignificant compared to the equity you lose when he draws out on you.

I think I'm on rise's side on this flop play.

I'm going to vomit if/when I get 3 bet on this flop. If this guy is playing aggro....I'm all for floating this flop. Any sort of broadway combo and an aggro player is 3 betting me putting me in a huge pickle. Obviously you lose value if you turn your nut flush, as the villain is going to proceed with extreme caution at that point with a small-ish pot, but if I know my villain is aggro enough to get it all in here with his QQ/JJ/QJ/combos, also with potential straight and OESD draws, I'd rather call here and re-eval on turn. If the villain is more ABC, then I'm willing to raise the flop to apply pressure, maximize value on my flush draw, and generally start juicing the pot with a strong post flop holding.
that said........
I'm not blind to dingus's stance, and I think the higher the stakes you are playing at, the more you would need to be popping this flop bet, otherwise you are probably going to get crushed long term calling down oppnents hands that "get there" and losing value when you make big hands after the flop. I think both sides of this argument hold a level of relevance and weight.