Think I got myself into a tough spot by trapping on the flop.
Small blind is 54/7/0, Big Blind is 43/15/9, ~250 hands each

[converted_hand][hand_history]Pacific, $0.05/$0.10 No Limit Hold'em Cash, 5 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite. View Hand #37231663

SB: $21.43 (214.3 bb)
BB: $12.57 (125.7 bb)
MP: $11.36 (113.6 bb)
CO: $9.57 (95.7 bb)
Hero (BTN): $20.60 (206 bb)

Preflop: Hero is BTN with A A
2 folds, Hero raises to $0.30, SB calls $0.25, BB calls $0.20

Flop: ($0.90) K 4 A (3 players)
SB bets $0.90, BB calls $0.90, Hero calls $0.90

I flatted here because I figured that I'm blocking a lot of their continuing ranges by raising? SB has donked with top pair before.

Turn: ($3.60) Q (3 players)
BB bets $1.80, Hero calls $1.80, SB folds

When the third heart came I realized I should have raised flop. I think SB's range at this point is mostly flushes? But I can't give up AA to one half pot bet, and if the board pairs I should be getting his whole stack.

River: ($7.20) 5 (2 players)
BB bets $5.60, Hero?

It seems impossible for SB to be bluffing, especially with the sizing up from halfpot to 3/4 pot. As for the value we beat, 44 is definitely plausible, but he 3bets KK, QQ, and probably AK preflop? I think that a 43/15/9 player might defend so many suited combos from the BB that we don't make it to the 30% we need to call. Can I fold here?

3way its so unlikely he does not have the flush...

Both look like pretty passive fish, and BBs line looks a lot like the flush.

If we dont look at the result of the hand, I think a raise otf is definitely better given the fact that its a multiway flop and by calling, they get pretty good odds to chase hands that can break you. Just go for it now while you certainely have the best hand.

As played, I would look at some more stats like 3bet percentage. If he does never 3bet, he might even have stuff like AQ, QQ, KQ,... Which might slightly justify a call. This might be possible based on his AF of 9.

Without knowing pretty sure if he would play them this way, I would fold.

Sorry, the 9 is his 3bet percentage, not his Aggression Factor. Don't have the AF stats for either villain.

Then I would fold, because he would 3bet with QQ and even AQ. There is not much left in his range that you would beat imo.

Just raise flop. Slowplaying topset is good sometimes, not here in mw with FD possible.

agree with raising flop. As played looks like a fold

100% raise flop because 3-way and flushdraw.

It Looks really strong by shoving the river, hard to fold but you have to

Raise flop

Raise flop on wet board and fold the river.