foxwoods 20/40, flop spot

[BigBadBabar]

hi guys, i was back at it the other night with nina [img]/images/graemlins/wink.gif[/img] (sorry ben) and i'm interested in your feedback on this hand. table was playing pretty limpy with no one standing out as crazy aggro or whatever. i didn't recognize anyone as a regular. my image is pretty tag/cold-decked for the last few hours having taken some gross beats.

3 limpers, then one kinda aggro guy raises, 1 coldcall, i coldcall 9[img]/images/graemlins/spade.gif[/img]7[img]/images/graemlins/spade.gif[/img], 3 limpers call.

6 to the flop of k[img]/images/graemlins/club.gif[/img]9[img]/images/graemlins/diamond.gif[/img]6[img]/images/graemlins/spade.gif[/img]
checked to the raiser who bets, 1 fold, and it's on me, and i what and why?

thanks.