Nut flush draw hits on river. Action?

[cheburashka]

Villain just joined table, and has played one of the last three hands, taking the pot without showing cards. Overall, the table has been limpy and passive; I have been playing 14/9/2.3.

UTG ($8.90 in chips)
UTG+1 ($25.45 in chips)
MP1 ($27.45 in chips)
MP2 ($25.45 in chips)
CO-1 ($24 in chips)
CO ($26.05 in chips)
BU ($15.90 in chips)
SB ($15.85 in chips)
Hero ($38.45 in chips)

Hero is BB with Jd Kd

UTG calls $0.25, two folds, MP2 calls $0.25, one fold, CO calls $0.25, BU calls $0.25, SB completes, Hero checks. (Very typical action for this table)

Flop ($1.50): Qd Ad Qs

SB checks, Hero bets $1.25, UTG calls $1.25, two folds, BU calls $1.25, one fold. (TAGGy semi-bluff, or spewy? I had seen whole tables of limpers clear out after a strong like this)

Turn ($5.25): Qd Ad Qs 4c

Hero checks, MP2 checks, BU bets $1.75, Hero calls $1.75, MP2 cals $1.75 (I figured that no-one who called my flop bet would fold to a second barrel on that turn card, so I checked. As to the call, I figured I’m getting 4:1 to see the river and a potential nut flush)

River ($10.50) Qd Ad Qs 4c 9d

Hero??? Also, what do you do if raised?