100NL: standard fold in a RR pot after smallish raise

[LuckySal]

READS: villian = 17/13-6 over +/-200 hands

Party Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 6 Players - (LegoPoker HH Converter)

SB: $96.25
<font color="black">Hero (BB): $118.20</font>
UTG: $127.65
MP: $100.00
CO: $213.90
BTN: $36.90

<font color="black">Preflop:</font> Hero is dealt A[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/club.gif[/img] (6 Players)
UTG folds, <font color="red">MP raises to $3.50</font>, 3 folds, <font color="red">Hero raises to $8.50</font>, MP calls $5.00

<font color="black">Flop:</font> ($17.50) J[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] (2 Players)
Hero checks, <font color="red">MP bets $8.00</font>, Hero calls $8.00

<font color="black">Turn:</font> ($33.50) 2[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $21.00</font>, <font color="red">MP raises to $50.00</font>, Hero folds???????

Pot Size: $104.50

One thing for sure, i should have 3-bet more preflop (to $11 or something, cause i am OOP, and most of the time i do.
But villian seemed a reasonable normal TAG, so i expected him to fold or to 4-bet. As i've seen him done before.
Now iam in a tough spot, and most of the time i feel people float me this way.

So what do u guys think.