Probably an easy decision

[Postiga]

I'm new to NL, and while I think I made a bad mistake here I'd like to hear what you think. Is this an instant fold, assuming no reads? It's Party $100 6max

Party Poker No-Limit Hold'em, $ Hero (6 max, 6 handed) FTR converter on zerodivide.cx

Hero ($104.40)
UTG ($18.04)
MP ($73.51)
CO ($127.70)
Button ($95.50)
SB ($102.80)

Preflop: Hero is BB with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/club.gif[/img]. SB posts a blind of $0.50.
UTG calls $1, <font color="#666666">2 folds</font>, <font color="#CC3333">Button raises to $5</font>, SB (poster) calls $4.50, Hero calls $4, UTG folds.

Flop: ($16) A[img]/images/graemlins/heart.gif[/img], 8[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets $9</font>, Button folds, SB calls $97.80 (All-In), Hero calls $88.80.

Turn: ($211.60) 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

River: ($211.60) 9[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

Final Pot: $211.60