Flush card completes my straight in 3way pot

[KyndGroove]

MP2 is 30.5/1.9/0.29 after 103
BTN is 20.1/10.1/2.67 after 117

Full Tilt 0.25/0.5 Hold'em (9 handed) Full Tilt Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Preflop: Hero is BB with T[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">3 folds</font>, MP2 calls, <font color="#666666">2 folds</font>, <font color="#CC3333">Button raises</font>, <font color="#666666">1 fold</font>, Hero calls, MP2 calls.

Flop: (6.40 SB) 8[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, MP2 checks, <font color="#CC3333">Button bets</font>, <font color="#CC3333">Hero raises</font>, MP2 calls, <font color="#CC3333">Button 3-bets</font>, Hero calls, MP2 calls.

Turn: (8.20 BB) J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP2 raises</font>, Button calls, Hero calls.

River: (14.20 BB) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">MP2 bets</font>, Button calls, Hero calls.

Final Pot: 17.20 BB

I checkraised the flop hoping to get HU with BTN who will often be cbetting UI Overs. If MP folded and BTN just called I planned to semibluff turn unless an ace fell. Is this a reasonable plan or should I always just call the flop?

Can I do anything other than call down when MP wakes up with a raise on the turn?