Value bet river with KK here?

[Nathan183]

Villain is very fishy, 60/3/1.

Party Poker No-Limit Hold'em, $ BB (10 handed) converter

UTG+1 ($54.1)
UTG+2 ($82.95)
MP1 ($26.6)
MP2 ($53.75)
MP3 ($46.4)
CO ($16.2)
Hero ($45.5)
SB ($91.6)
BB ($128.6)
UTG ($81.2)

Preflop: Hero is Button with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.25.
<font color="#666666">1 fold</font>, UTG+1 calls $0.50, <font color="#666666">4 folds</font>, CO calls $0.50, <font color="#CC3333">Hero raises to $2</font>, <font color="#666666">2 folds</font>, UTG+1 calls $1.50, CO calls $1.50.

Flop: ($6.75) Q[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
UTG+1 checks, CO checks, <font color="#CC3333">Hero bets $5</font>, UTG+1 calls $5, CO folds.

Turn: ($16.75) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
UTG+1 checks, <font color="#CC3333">Hero bets $10</font>, UTG+1 calls $10.

River: ($36.75) 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
UTG+1 checks, Hero?

Checking behind seems really weak, but I don't like that river card, and would hate to be check-raised here.