ATs hitting 2pair, time to fold? 100NL

[Morrek]

BB is 50/10 and 33% wtsd over 50ish hands, I have a note on him as "weak/passive?", I don't remember why I wrote it however. He seemed, I dunno, weird? Hadn't really seen him play much as I'm 3tabling.

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) FTR converter on zerodivide.cx

Hero ($105.95)
CO ($66.50)
Button ($60.37)
SB ($76.95)
BB ($105.33)
UTG ($105.55)

Preflop: Hero is MP with A[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.50.
UTG calls $1, <font color="#CC3333">Hero raises to $5</font>, <font color="#666666">3 folds</font>, BB calls $4, UTG folds.

Flop: ($11.50) 9[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $11</font>, BB calls $11.

Turn: ($33.50) K[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
BB checks, <font color="#CC3333">Hero bets $23</font>, BB calls $23.

River: ($79.50) T[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
BB calls $66.33 (All-In), Hero ?

Final Pot: $145.83


Bet more on turn? Call river? Fold? I'm thinking he could have a range of hands here, some including weird 2pairs, and also ofcourse, the flush. Ideas?