nl10: two pair facing big river bet

[Mr.o0]

hey guys.i just moved down from nl50 to nl10 to improve my multitabling game and to reevaluate my style.villain is pretty aggro and calls a lot before the flop. i have never seen him making such a big bet on the river.thought on all streets please

Party Poker, $0.05/$0.10 NL Hold'em Cash Game, 8 Players
LeggoPoker.com - Hand History Converter

CO: $9.72
BTN: $1.70
SB: $11.93
BB: $10.36
UTG: $1.78
Hero (UTG+1): $12.12
MP1: $2.45
MP2: $2.03

Pre-Flop: 5[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/heart.gif[/img] dealt to Hero (UTG+1)
UTG folds, Hero calls $0.10, MP1 folds, MP2 calls $0.10, CO calls $0.10, BTN folds, SB calls $0.05, BB checks

Flop: ($0.50) 8[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/club.gif[/img] 6[img]/images/graemlins/club.gif[/img] (5 Players)
SB checks, <font color="red">BB bets $0.50</font>, Hero calls $0.50, 3 folds

Turn: ($1.50) A[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">BB bets $0.50</font>, <font color="red">Hero raises to $1.70</font>, BB calls $1.20

River: ($4.90) 5[img]/images/graemlins/spade.gif[/img] (2 Players)
<font color="red">BB bets $4</font>, Hero folds