He's oh so passive

[Saborion]

Party Poker 5/10 Hold'em (6 max, 6 handed) FTR converter on zerodivide.cx

UTG: ~45/3/x. Is loose post but can fold on turn.
MP: ~60/0/1. Doesn't like to fold. 58/42 WSD/W$SD. Not too many hands logged.
CO: unknown.
Button: 27/11/2 and 16/75 WSD/W$SD. Only 75 hands.

Preflop: Hero is BB with 6[img]/images/graemlins/club.gif[/img], J[img]/images/graemlins/club.gif[/img].
UTG calls, MP calls, <font color="#666666">1 fold</font>, Button calls, SB completes, Hero checks.

Flop: (5 SB) 4[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(5 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, UTG calls, MP calls, Button calls, SB folds.

Turn: (4.50 BB) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, UTG checks, <font color="#CC3333">MP bets</font>, <font color="#CC3333">Button raises</font>, Hero calls, UTG folds, MP calls.

River: (10.50 BB) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">MP bets</font>, Button calls. Do we call?

What about the other streets? I bet the flop since I knew I would get at least 3 callers. Turn, no point betting. River, do we have a call? So far I haven't seen MP make any aggressive moves at all really. Not that I can recall anyway. Button only calling this river bet suggest that he has no better than Tx.