Worthwhile bluff or just stupid?

[Biggle10]

Is my blind defense too loose here? I believe it is, but want to double check. Villian is a SLAG.

PokerStars 2/4 Hold'em (9 handed) converter

Preflop: Hero is SB with A[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">5 folds</font>, <font color="#CC3333">CO raises</font>, <font color="#666666">1 fold</font>, Hero calls, <font color="#666666">1 fold</font>.

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

Turn: (4.50 BB) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>....

Fold to a turn raise, check/fold river if no ace.

[shant]

I think you should 3-bet or fold preflop.

[TheHammer24]

I'm three betting or folding preflop. If I 3-Bet i'm leading. If he caps, i may c/f if no A falls. If A falls depending on Turn and river, it would probably be a c/c c/c bet