100NL facing river c/r

[aceskay]

Villain is unknown. This line seems very strange to me. Is this an easy call on the river? Could he have made worse 2-pair? Is this nearly always the straight?

I was very confused by this river bet. I mean if he flopped a big hand or was helped out by the turn wouldn't I have heard from him sooner?

Does anyone fold here?

Full Tilt No-Limit Hold'em, $1 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP ($52.85)
CO ($93.40)
Button ($101)
SB ($215.10)
BB ($20.70)
Hero ($194.20)

Preflop: Hero is UTG with A[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">Hero raises to $3.5</font>, <font color="#666666">3 folds</font>, SB calls $3, BB calls $2.50.

Flop: ($10.50) 8[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">SB bets $4</font>, BB calls $4, Hero calls $4.

Turn: ($22.50) A[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, BB checks, <font color="#CC3333">Hero bets $12</font>, SB calls $12, BB folds.

River: ($46.50) J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, <font color="#CC3333">Hero bets $21</font>, <font color="#CC3333">SB raises to $65</font>, Hero ???