Grabbed by Holdem Manager
NL Holdem $0.50(BB) Replayer
SB ($24.80)
BB ($50)
UTG ($76.76)
Hero ($162.19)
BTN ($146.23)

Dealt to Hero A 5

fold, Hero raises to $1.50, BTN calls $1.50, SB calls $1.50, BB calls $1.50

FLOP ($6.00) Q 9 3

SB checks, BB checks, Hero bets $4.50, BTN calls to $4.50, SB folds, BB folds

TURN ($15.00) Q 9 3 K

Hero bets $11.50, BTN calls to $11.50

RIVER ($38.00) Q 9 3 K 7

Hero bets $32.00, BTN raises to $128.73(AI), Hero ???

Villain is 18/16 3b:5.6 over ~800. Haven't seen him go out of line. I think a worse flush would probably just call river, so this would mean this is the nuts or a bluff? But for this to be a bluff, villain would need to know that I would capable of folding a flush right? Is this ever be a bluff? Can we fold to 1 combo here or do we call and chalk it up as a cooler if he has the nuts? Am I wrong for thinking that villain won't be doing this with worse (or maybe something I left out again)?