Do I let my inner station out?

[cooker3]

Poker Stars - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $78.20
hero (BB): $53.75
UTG: $50.00
MP: $56.15
CO: $94.00
BTN: $34.25

Reads: <font color="blue">I am 27/22/10 over 40 or so hands
My opponant is 38/5/2 over 18 hands
Played 1 other hand previously where he min raised my continuation bet and I folded</font>

Preflop: hero is dealt 5 3[img]/images/graemlins/spade.gif[/img] (6 Players)
3 folds, BTN calls $0.50, SB folds, <font color="red">hero raises to $2.50</font>, BTN calls $2.00

Flop: ($5.25) 5[img]/images/graemlins/spade.gif[/img] 9 6 (2 Players)
<font color="red">hero bets $3.50</font>, BTN calls $3.50

Turn: ($12.25) 5[img]/images/graemlins/spade.gif[/img] 9 6 K[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">hero bets $7.50</font>, BTN calls $7.50

River: ($27.25) 5[img]/images/graemlins/spade.gif[/img] 9 6 K[img]/images/graemlins/spade.gif[/img] J (2 Players)
hero checks, <font color="red">BTN bets all-in for $20.75</font>

Pot Size: $48.00

Ok so I really really wanted to call this at the time. His hand looks like it could be a draw to me a lot. A set seems unlikely as I would have thought he raise me somewhere on the previous 2 streets, a 9 would surely check behind, the same for pairs of 7's and 8's
What he could have that beats me, a made straight is possible but again I would have thought there would have been raised but it's a possibility, a k high flush draw that hit on the turn is possbility. Maybe some J high flush draw which hit on the river.
I am getting 2.3-1 to call roughly.
Would it be good or spew?