AP .25/.50 - ok to CRAI the river?

[alex-star]

The villain is 40/15 over 70 hands or so.

Absolute Poker
No Limit Holdem Ring game
Blinds: $0.25/$0.50
8 players
Converter

Stack sizes:
UTG: $47.20
UTG+1: $34.95
MP1: $27.80
MP2: $19.50
CO: $16.45
Button: $90.70
SB: $30.85
Hero: $56.25

Pre-flop: (8 players) Hero is BB with A[img]/images/graemlins/spade.gif[/img] 3[img]/images/graemlins/spade.gif[/img]
2 folds, <font color="#cc0000">MP1 raises to $2</font>, 3 folds, SB calls, Hero calls.

Flop: 5[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/heart.gif[/img] 5[img]/images/graemlins/diamond.gif[/img] ($6, 3 players)
SB checks, Hero checks, <font color="#cc0000">MP1 bets $1.5</font>, SB folds, <font color="#cc0000">Hero raises to $4.5</font>, MP1 calls.

Turn: 3[img]/images/graemlins/club.gif[/img] ($15, 2 players)
<font color="#cc0000">Hero bets $5.5</font>, MP1 calls.

River: A[img]/images/graemlins/heart.gif[/img] ($26, 2 players)
Hero checks, <font color="#cc0000">MP1 bets $4</font>, Hero ??