NL50: 15 outer on paired board makes weak straight, can I fold here?

[Specialwon]

Less than 20 hands on villain who seemed somewhat loose passive. Not too many hands would make him jump up like that on the river I'm thinking.

Comments on other streets appreciated too.

Poker Room skin
No Limit Holdem Ring game
Blinds: $0.25/$0.50
10 players
Converter

Stack sizes:
UTG: $51.95
UTG+1: $18.65
UTG+2: $28.60
MP1: $47.25
MP2: $81.00
MP3: $50.50
CO: $5.00
Button: $31.80
Hero: $48.25
BB: $48.50

Pre-flop: (10 players) Hero is SB with Q[img]/images/graemlins/heart.gif[/img] T[img]/images/graemlins/heart.gif[/img]
UTG folds, UTG+1 calls, UTG+2 calls, MP1 folds, MP2 calls, MP3, folds, CO (poster) checks, Button folds, Hero calls, BB (poster) checks.

Flop: 9[img]/images/graemlins/heart.gif[/img] J[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] ($3, 6 players)
<font color="#cc0000">Hero bets $2.5</font>, 2 folds, UTG+2 calls, MP2 calls, CO folds.

Turn: T[img]/images/graemlins/spade.gif[/img] ($10.5, 3 players)
Hero checks, <font color="#cc0000">UTG+2 bets $4.5</font>, MP2 calls, Hero calls.

River: K[img]/images/graemlins/diamond.gif[/img] ($24, 3 players)
Hero checks, <font color="#cc0000">UTG+2 is all-in $21.1</font>, MP2 folds, Hero would like to fold.