bloody JJ and overcard on flop

how would you play the turn here?
my first instinct was to bet and then fold to a raise/check-raise but i chickened out. considering he cold called, chances he had a K were pretty high anyway.. or am i wrong? should i have followed my instincts?

Party Poker 2/4 Hold'em (10 handed) converter

Preflop: Hero is MP2 with J[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises</font>, MP3 calls, <font color="#666666">2 folds</font>, SB calls, <font color="#666666">1 fold</font>, UTG+1 calls.

Flop: (9 SB) 4[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, UTG+1 checks, <font color="#CC3333">Hero bets</font>, MP3 calls, SB calls, UTG+1 folds.

Turn: (6 BB) 2[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, Hero checks, <font color="#CC3333">MP3 bets</font>, SB folds, Hero folds.

Final Pot: 7 BB