weak flush on turn 3-ways

I am not sure I like my turn line here. 3-bet/fold to a cap on the turn? I called intending to bet/call most non-spade rivers.

MP2 is (VPIP 55%, PFR 7%, AF .67)
MP1 is (VPIP 70%, PFR 3%, AF .37)

Party Poker 2/4 Hold'em (7 handed) FTR converter on zerodivide.cx (http://www.zerodivide.cx/converter)

Preflop: Hero is SB with T/images/graemlins/spade.gif, 8/images/graemlins/spade.gif.
<font color="#666666">1 fold</font>, MP1 calls, MP2 calls, <font color="#666666">2 folds</font>, Hero completes, BB checks.

Flop: (4 SB) 6/images/graemlins/spade.gif, 2/images/graemlins/club.gif, 7/images/graemlins/spade.gif <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, BB folds, MP1 calls, MP2 calls.

Turn: (3.50 BB) 2/images/graemlins/spade.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, MP1 calls, <font color="#CC3333">MP2 raises</font>, Hero calls, MP1 calls.

River: (9.50 BB) 3/images/graemlins/spade.gif <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">MP1 bets</font>, <font color="#CC3333">MP2 raises</font>, Hero folds, <font color="#CC3333">MP1 3-bets</font>, MP2 calls.

Final Pot: 15.50 BB