Stars $50 - 55 OOP, but flop checked

[JSampras1]

Initial raiser i only have 70 hands, but he is a nitty, 11%/5%/AF 1 and it was even less before that raise. The 2 callers I only have 10 hands on, but i just saw button call a raise with QJ, and SB was calling bets on an AK5 flop with k3. So those guys are both pretty loose and crappy.

PokerStars No-Limit Hold'em, $0.50 BB (7 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP2 ($17.40)
CO ($66.95)
Button ($20)
SB ($21.15)
BB ($50)
Hero ($61.40)
MP1 ($53.50)

Preflop: Hero is UTG with 5[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/diamond.gif[/img].
Hero calls $0.50, <font color="#666666">2 folds</font>, <font color="#CC3333">CO raises to $2</font>, Button calls $2, SB calls $1.75, <font color="#666666">1 fold</font>, Hero calls $1.50.

I called looking for the set. Hopefully raiser stacks off AA here.

Flop: ($8.50) J[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, Hero checks, CO checks, Button checks.

I miss, prepare to c/f, but everyone checks. I am almost sure if raiser liked his hand he bets. I start getting ready to bet 5-6 on the turn. Then i think about it. I am almost sure the raiser will fold, but there's a lot of high cards out there, and 2 terrible players that just showed they are willing to call at least small bets with any pair. If they missed, they may even check again. Do you think it's worth betting here?

Turn: ($8.50) 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, Hero checks, CO checks, Button checks.

River: ($8.50) 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, Hero checks, CO checks, Button checks.

Given that i checked the turn, i thought there's no reason to bet here. If they missed, they probably check. If they hit, i doubt they're folding. Was this an obvious steal opportunity i missed here?

Just in case ppl think i'm being results oriented. It actually was checked around and i won. I'm just wondering if i missed an obvious bluff here.