NL25 AK - OCs+2ndNutFD against midstack

[OMGJuliet]

PokerStars No-Limit Hold'em, $0.25 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Hero ($26.35)
MP ($37.35)
Button ($58.50)
SB ($13.50)
BB ($26.05)

Preflop: Hero is UTG with A[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#CC3333">Hero raises to $1</font>, <font color="#666666">1 fold</font>, Button calls $1, SB calls $0.90, <font color="#666666">1 fold</font>.

Flop: ($3.25) T[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/club.gif[/img], 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB bets $3.5</font>, <font color="#CC3333">Hero raises to $12.5</font>, Button folds, SB calls $9 (All-In).

Turn: ($0) 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

River: ($0) 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

Final Pot: $28.25

I was wondering whether i could fold. Calling is no Option. I certainly am not Pot-Committed but he may donk with a combo-draw and my OC-Outs may still be good if he is playing JJ or some kind of Odd pair. Why would someone donk with a made flush in this spot, it'd only save Overcards oder Overpairs the money of continuation betting, since his money will get in anyways by the river with his small stack.

What do you think?