Straight on a 3 flush board

[closer2313]

Table was fairly loose and not very aggressive.

I haven't played with either of the villians.

On the turn I have the nut straight, but it puts 3 to a flush on board. It also puts 4 to the straight on the board. I figure I should bet out in this spot. If its raised behind me, or 3 bet behind me, what should I do? The raise could easily mean a bare 9, but a 3 bet could mean a flush.

Probably read dependent on who is raising, but whats my general line here?

Thanks

PokerStars 0.25/0.50 Hold'em (10 handed) converter

Preflop: Hero is BB with T[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/spade.gif[/img].
UTG calls, UTG+1 calls, UTG+2 calls, MP1 calls, <font color="#666666">4 folds</font>, SB completes, Hero checks.

Flop: (6 SB) 8[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(6 players)</font>
SB checks, Hero checks, <font color="#CC3333">UTG bets</font>, UTG+1 calls, UTG+2 calls, MP1 calls, SB calls, Hero calls.

Turn: (6 BB) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(6 players)</font>
SB checks, Hero ????