RVB Question Versus Tight Passives

[toss]

Both villains are tight, passive postflop, and have low showdown rates (20, 28) after 50 or 100 hands. Ask me if you want to see stats.

Party Poker 5/10 Hold'em (6 max, 6 handed) converter

Preflop: Hero is Button with K[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/diamond.gif[/img]. CO posts a blind of $5.
UTG calls, <font color="#666666">1 fold</font>, CO (poster) checks, <font color="#CC3333">Hero raises</font>, SB calls, BB calls, UTG calls, CO calls.

Flop: (10 SB) A[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, BB checks, UTG checks, CO checks, Hero checks.

Turn: (5 BB) K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, BB checks, UTG checks, CO checks, <font color="#CC3333">Hero bets</font>, SB calls, BB calls, UTG folds, CO folds.

River: (8 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, BB checks, Hero checks.

Final Pot: 8 BB

Should I just bet anyways?