Flop bottom pair +GS

[Fadook]

.5/1 4-handed.

BB is an ok player, 29/18. I feel he bluffs a bit too often, doesn't lay down often enough, and is overly aggressive against passive opponents.

CO is 70/0 over 80 hands. Unbelievably passive, I've never seen him raise preflop, and that includes premium hands. Postflop he's also extremely loose and passive and always slowplays strong hands until the river. He's occasionally made a total bluff bet on the river.

Hero is SB with 8[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/spade.gif[/img]
CO calls, BTN folds, Hero calls, BB checks.

Flop (3 SB): 5[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/heart.gif[/img] 9[img]/images/graemlins/club.gif[/img]
Hero checks, BB bets, CO calls.

Anyone lead the flop? If not against this lineup, what type of players would you want to bet the flop?
Regardless, what's the plan for the rest of the hand? I could easily see BB taking a stab here with a draw or even A-hi. Should I go to the river?