Should I bet this river?

[MexKrax]

MP1 is very loose-passive. Other players are also loose passive, not that that really matters here.

I chickened out betting the river when the third spade hit, was this a good move or weak tight?

If MP1 raises on the river do you fold or call?

Party Poker 0.5/1 Hold'em (10 handed) converter

Preflop: Hero is BB with K[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">1 fold</font>, MP1 calls, MP2 calls, MP3 calls, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises</font>, UTG+1 calls, MP1 calls, MP2 calls, MP3 calls.

Flop: (10.50 SB) 4[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 calls, MP1 calls, MP2 calls, MP3 folds.

Turn: (7.25 BB) 8[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG+1 folds, MP1 calls, MP2 folds.

River: (9.25 BB) 2[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero???

Final Pot: 9.25 BB