Overpair to board, 3 to flush. bet river or not?

Only at this room for 10 minutes or so. Had not noticed anything special, just normal .25/.50 play so far. ie lots of callers.
Converter took out my cards, i had KK in UTG+2.

PokerRoom 0.25/0.50 Hold'em (10 handed) FTR converter on zerodivide.cx

Preflop: is with ,
calls, UTG+1 calls, <font color="#CC3333">dabeards raises</font>, <font color="#666666">5 folds</font>, SB calls, BB calls, calls, UTG+1 calls.

Flop: (10 SB) Q[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, BB checks, checks, <font color="#CC3333">UTG+1 bets</font>, <font color="#CC3333">dabeards raises</font>, SB folds, BB calls, calls, UTG+1 calls.

I put UTG+1 on a Q, not sure of kicker though. And maybe one of the callers on the flush draw??

Turn: (9 BB) 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, checks, UTG+1 checks, <font color="#CC3333">dabeards bets</font>, BB calls, calls, UTG+1 calls.

Scare card here, kept UTG+1 from betting so pretty sure he has a Q and not a club draw. Was expecting a check raise from someone here after my bet.

River: (13 BB) 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
BB checks, checks, UTG+1 checks.

Final Pot: 13 BB

I figured if I bet the river I either get called by a flush or check raised. Should I have raised it here or not??

[Redd]

Bet, and get called by a Q, a 6, and A-high. You'll usually see aggression on the turn from a flush.

Bet the river, but I'm not raising a check-raise.

[Songwind]

bet/call the river.

Bet/call the river.

Grunch:

With no shown aggression on the turn, I think I bet the riv. I'm not giving many .25/.5 players that much credit to pull off a delayed raise.