100nl FH in limped pot

[Womble]

Party Poker - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 5 Players - (LegoPoker HH Converter)

SB: $115.56
Hero (BB): $98.50
UTG: $101.47
CO: $43.55
BTN: $130.57

Reads: <font color="blue">No reads at the time - guy was 44/2/0.5 over 100 hands at the end of the session. What do you do after the river 3bet?</font>

Preflop: Hero is dealt 2[img]/images/graemlins/spade.gif[/img] 6[img]/images/graemlins/club.gif[/img] (5 Players)
UTG calls $1.00, 2 folds, SB calls $0.50, Hero checks

Flop: ($3) A[img]/images/graemlins/diamond.gif[/img] 3[img]/images/graemlins/spade.gif[/img] 6[img]/images/graemlins/spade.gif[/img] (3 Players)
SB checks, Hero checks, UTG checks

Turn: ($3) 2[img]/images/graemlins/club.gif[/img] (3 Players)
<font color="red">SB bets $2.00</font>, Hero calls $2.00, UTG folds

River: ($7) 6[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">SB bets $3.00</font>, <font color="red">Hero raises to $12.50</font>, <font color="red">SB raises to $36.00</font>