25nl confused on river

[rpm]

villain is 16/10/3 over 125. folded to 2/6 flop CB's and 2/4 turn CB's. hasn't raised a CB. he sees me as 28/24/6 with a large ATS. he has seen me overbet a river on a dry board w/o shodown where i could only rep FH's/air (hand is here: http://www.flopturnriver.com/pokerfo...eg-191570.html ). BB is a 32/1 fit or fold fish. in play i felt like making what i thought was a thinnish vbet, immediately after the hand (lol results oriented) i felt like bluffing big with my blocker attempting to fold out 44/KQ and mid-range flushes. (although i have already fired 3 overbetting the river vs him in the last 100 hands so he might get a bit weird about me doing that). now i don't know what i should have done. what's our river play?

PokerStars - $0.25 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

UTG: $6.82
MP: $25.35
Hero (CO): $54.52
BTN: $36.30
SB: $14.72
BB: $25.60

SB posts SB $0.10, BB posts BB $0.25

Pre Flop: (pot: $0.35) Hero has A A

fold, fold, Hero raises to $0.75, BTN calls $0.75, fold, BB calls $0.50

Flop: ($2.35, 3 players) 4 K Q
BB checks, Hero bets $2.00, BTN calls $2.00, fold

Turn: ($6.35, 2 players) 7
Hero bets $3.25, BTN calls $3.25

River: ($12.85, 2 players) 9
Hero?