K7o 4-flush turn check

[tizim]

Everyone besides villain is super loose-passive.

Villain is 70/2 preflop, but a nutty LAG postflop. He capped AK on a 733 flop 3-way, and I've also seen him bluff all 3 streets against 2 players.

Bet the turn? Check the turn, bet/call the river? Fold preflop?

Party Poker 10/20 Hold'em (6 max, 6 handed) converter

Preflop: Hero is SB with 7[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#666666">1 fold</font>, CO calls, Button calls, Hero completes, BB checks.

Flop: (5 SB) 2[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">BB raises</font>, UTG folds, CO folds, Button folds, <font color="#CC3333">Hero 3-bets</font>, BB calls.

Turn: (5.50 BB) 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">BB bets</font>, Hero calls.

River: (7.50 BB) J[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, BB checks.

Final Pot: 7.50 BB