50NL: weird hand against donkey

[ShallowMalePig]

Bodog 50NL, fullring.

My stack is 51 dollars, villian's is 37. I've seen him making questionable plays before. Kinda donkeyish - called an allin on an ace high board with A2o and stacked off versus a set. I've been raising the past few hands because, well, I've been getting good cards.

On to the hand. I have A [img]/images/graemlins/heart.gif[/img] 8 [img]/images/graemlins/heart.gif[/img] from the cutoff, one limper, and I raise to 2.25 (standard potsized raise). Villian in small blind calls, everyone else folds. Flop comes 8 [img]/images/graemlins/spade.gif[/img] 3 [img]/images/graemlins/spade.gif[/img] 2 [img]/images/graemlins/club.gif[/img]. Villian bets 1.8, I raise to 5.75, villian calls (potsize = 17).

Turn comes 5 [img]/images/graemlins/club.gif[/img]. Villian bets 2.05. I call (potsize 21).

River J [img]/images/graemlins/diamond.gif[/img] . Villian goes insta-allin in for his remaining 27 dollars.

Hero?