Raise for a free showdown? ($10/20 5 handed, A3s blind steal)

[TheMetetron]

I normally think plays like this are dumb, but I can't think of a better line for a host of reasons. I plan to see if I can make more plays like this in the future.

FWIW, I was folding to a turn 3-bet. On the river I fold if the flush completes and he donks. Probably call otherwise unless it's like a Q or something. If he checks, I was checking behind without further improvement.

Party Poker 10/20 Hold'em (6 max, 5 handed) converter

Preflop: Hero is MP with A[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/spade.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, SB calls, BB calls.

Flop: (6 SB) 3[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">SB raises</font>, BB folds, Hero calls.

Turn: (5 BB) K[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets</font>, <font color="#CC3333">Hero raises</font>...