Fire a 3rd shot?

[NLHE lahooozaher]

Opp is 31/7/3.xx over ~500 hands. Trying to put him on a hand on the river. I can't figure out what he has and what he thinks I have for him to play so passively.

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP ($25)
CO ($25)
Button ($55.80)
SB ($9)
BB ($57.20)
Hero ($32.50)

Preflop: Hero is UTG with Q, J.
Hero raises to $1, 2 folds, Button calls $1, 2 folds.

Flop: ($2.35) 2, K, 7 (2 players)
Hero bets $1.75, Button calls $1.75.

Turn: ($5.85) 9 (2 players)
Hero bets $4, Button calls $4.

River: ($13.85) K (2 players)
Hero...

[IowaSkinsFan]

no, bad time to three barrel. He's probably a fish and the K on the river is just going to make him more inclined to call u with a 9/7. You're beating a few draws anyway.