Flop set of 9's on scary board

[Clownfish]

No real read on either player.

Do you 3 bet the turn here or raise river?

This was the last hand I was playing for the night and was too lazy to raise preflop although this would have cleared up his possible hands a little. A 3 bet preflop would have most likely eliminated hands like a7 or 77 which were the only likely 7's he could have had.

Party Poker 0.50/1 Hold'em (10 handed) converter

Preflop: Hero is UTG with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
Hero calls, <font color="#CC3333">UTG+1 raises</font>, UTG+2 calls, <font color="#666666">2 folds</font>, MP3 calls, <font color="#666666">3 folds</font>, BB calls, Hero calls.

Flop: (10.50 SB) 8[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>
BB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG+1 raises</font>, UTG+2 calls, MP3 folds, BB folds, <font color="#CC3333">Hero 3-bets</font>, UTG+1 calls, UTG+2 calls.

Turn: (9.75 BB) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG+1 raises</font>, UTG+2 calls, Hero calls.

River: (15.75 BB) 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">UTG+1 bets</font>, UTG+2 calls, Hero calls.

Final Pot: 18.75 BB