NL50. Odd hand vs raiser. I make two pair on end...but big bet

[Haplo]

Villain is 42/14/3.3 in 72 hands.


Full Tilt No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB ($11.25)
UTG ($53.80)
UTG+1 ($30.75)
MP1 ($139.50)
MP2 ($76.60)
MP3 ($31.30)
Hero ($74.20)
Button ($28.60)
SB ($49.50)

Preflop: Hero is CO with 8[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/heart.gif[/img].
<font color="#666666">2 folds</font>, <font color="#CC3333">MP1 raises to $1.75</font>, <font color="#666666">2 folds</font>, Hero calls $1.75, <font color="#666666">3 folds</font>.

Flop: ($4.25) 8[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/club.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $4.25</font>, Hero calls $4.25.

Turn: ($12.75) 4[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $12.75</font>, Hero calls $12.75.

River: ($38.25) A[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $38.25</font>, Hero ????

This was a weird bet, and I wasn't sure how to respond. Did he actually make a flush? (weird betting if he did). Did he make trip aces? (that would explain the flop and turn bets--but why bet the river?) Then again, this guy's numbers aren't too good.

Comments appreciated.