NL 50, make aces up on the river

[starkwired]

Villain seems loose (27/10/2 over like 50 hands), but no real strong reads.

Poker Stars - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 4 Players - (LegoPoker Hand History Converter)

SB: $14.10
BB: $52.55
Hero (UTG): $69.50
BTN: $83.55

Preflop: Hero is dealt A[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/spade.gif[/img] (4 Players)
<font color="red">Hero raises to $2.00</font>, 2 folds, BB calls $1.50

Flop: ($4.25) 6[img]/images/graemlins/heart.gif[/img] 7[img]/images/graemlins/spade.gif[/img] A[img]/images/graemlins/diamond.gif[/img] (2 Players)
BB checks, <font color="red">Hero bets $2.50</font>, BB calls $2.50

Turn: ($9.25) 4[img]/images/graemlins/diamond.gif[/img] (2 Players)
BB checks, <font color="red">Hero bets $6.00</font>, <font color="red">BB raises to $16.00</font>, Hero calls $10.00

River: ($41.25) 5[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">BB bets all-in for $32.05</font>, Hero ?

I feel like this is an easy fold, but I also feel like he put me on nothing and makes this PSB with any ace.