River flush whats the most optimal way to play this?

[Hooked]

Villain is 25 / 16 / 2.25 over 75 hands
then this hand came up please give me feed back on all streets
Full Tilt Poker, $0.50/$1 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

CO: $312.80
BTN: $104.70
SB: $123.35
BB: $54.80
Hero (UTG): $108.05

Pre-Flop: J[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/heart.gif[/img] dealt to Hero (UTG)
<font color="red">Hero raises to $3.50</font>, 2 folds, SB calls $3, BB folds

Flop: ($8) 2[img]/images/graemlins/spade.gif[/img] 2[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] (2 Players)
SB checks, Hero checks

Turn: ($8) 7[img]/images/graemlins/heart.gif[/img] (2 Players)
SB checks, <font color="red">Hero bets $6</font>, <font color="red">SB raises to $21</font>, Hero calls $15

River: ($50) A[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">SB bets $38</font>, <font color="red">Hero??

DO i push here or just call, comments on all streets welcomed

[Hattifnatt]

def no value in a raise.