TPGK with a bad feeling...what is your line here?

[Propster]

I don't really have a read on this guy, but for some reason, i have that feeling I'm getting out-kicked... What's your line on flop/turn here? I suppose a flop raise would be a good move if i wanted more information...

I know this is a fairly simple hand, but inputs would be appreciated!

PokerRoom No-Limit Hold'em, $1 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

UTG ($101.80)
MP ($64.90)
Button ($98.65)
SB ($103.00)
Hero ($108.10)

Preflop: Hero is BB with K[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">SB raises to $3.5</font>, Hero calls $2.50.

Flop: ($7) K[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $5</font>, Hero calls $5.

Turn: ($17) 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $12</font>, Hero ???