25nl AQs UTG raise brings 5 and faces lead bet on A-high 3heart flop

[SumZero]

Ultimate Bet No-Limit Hold'em, $.25 BB (9 handed) internettexasholdem.com

CO ($37.60)
Button ($40.70)
SB ($16.50)
BB ($5.80)
Hero ($71.25)
UTG+1 ($13.95)
MP1 ($24.75)
MP2 ($11.15)
MP3 ($26.30)

Preflop: Hero is UTG with Q[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
<font color="#CC3333">Hero raises to $0.85</font>, UTG+1 calls $0.85, <font color="#666666">2 folds</font>, MP3 calls $0.85, CO calls $0.85, <font color="#666666">1 fold</font>, SB calls $0.75, <font color="#666666">1 fold</font>.

Flop: ($4.50) A[img]/images/graemlins/heart.gif[/img], T[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">SB bets $2.75</font>, Hero ???

The SB had just played a hand versus me where he bluffed a small position mini-bet on the flop with a K5s that had totally missed everything and beat me by hitting the K on the turn.