Will a raise let him off too easily?

[Logik]

Villian is really really loose, and tilting from losing two buyins very very recently. He has been betting a lot with air, but I don't know if he would 3-bet bluff.

Pokerstars 50NL 6-max

BB ($51.55)
UTG ($82.90)
MP ($54.05)
CO ($82.30)
Button ($49.25)
Hero ($58.80)

Preflop: Hero is SB with Q[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/club.gif[/img].
UTG calls $0.50, MP calls $0.50, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises to $2.5</font>, <font color="#666666">1 fold</font>, UTG calls $2, MP calls $2.

Preflop: I really should have bumped it to $3.25 or $3.50 here because of both limpers, but lets not comment on that.

Flop: ($8) 6[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets $8</font>, UTG calls $8, MP folds.

Turn: ($24) Q[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>

Hero...? (He likely has K-high, or maybe A-high)