Lets talk about sets baby

[PokerBob]

Canterbury 15/30 (9 handed)
CO here is a dick. He also plays loose (limps K4s in EP). Doesn't do anything insane postflop. SB here is a nice guy but a nut. VPIP has to be near 80 and will get very aggressive with draws and TP.

folds to MP who limps, CO limps, I limp 3 [img]/images/graemlins/heart.gif[/img]3 [img]/images/graemlins/club.gif[/img] on the button, SB calls, BB checks.

Flop (5 players) (5 SB): J [img]/images/graemlins/spade.gif[/img]7 [img]/images/graemlins/diamond.gif[/img]3 [img]/images/graemlins/club.gif[/img]

checks, to CO who bets, I call, SB check/raises, BB and MP fold, CO 3-bets, I.....hit the gas now or on the turn?

EDIT: I should mention that CO has 4 bets in front of him at the start of this hand. He's also a dick.