Stars 50NLCASH AA scary board

[kleath]

We've played about 55 hands so far and he's been fairly passive for the most part, I've 3bet him about 5 times, 3 times he folded pre, 1 time he called then folded flop 1 time he raised my cbet. He has shown down maybe 4 or 5 hands and hasnt won at showdown, no big pots went to sd. Also I don't think at this point he had ever bluffed turn or river. Turn and river don't seem right as played, what should my line be from the turn on?

PokerStars No-Limit Hold'em, $0.50 BB (2 handed) internettexasholdem.com

Button ($226.45)
Hero ($71)

Preflop: Hero is BB with A[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/heart.gif[/img].
<font color="#CC3333">Button raises to $1.5</font>, <font color="#CC3333">Hero raises to $5</font>, Button calls $3.50.

Flop: ($10) K[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/club.gif[/img], 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $6</font>, Button calls $6.

Turn: ($22) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, Button checks.

River: ($22) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, Button checks.

Final Pot: $22