Party NL $50, four-tabling. Both villains are laggy.

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) internettexasholdem.com

MP ($21.38)
CO ($233.87)
Button ($48.45)
Hero ($106.82)
BB ($36.75)
UTG ($125.93)

Preflop: Hero is SB with 6[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img]. Hero posts a blind of $0.25.
UTG calls $0.50, <font color="#666666">1 fold</font>, CO calls $0.50, Button calls $0.50, Hero (poster) completes, BB checks.

Flop: ($2.50) 4[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(5 players)</font>
Hero checks, BB checks, UTG checks, <font color="#CC3333">CO bets $2.4</font>, Button calls $2.40, Hero calls $2.40, <font color="#CC3333">BB raises to $7</font>, UTG folds, CO calls $4.60, Button folds, Hero calls $4.60.

Okay, so somebody definitely has a four, and I'm gonna take all their chips, right? So now what:

Turn: ($25.90) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
Hero ???

What's my line for the rest of the hand? And is my flop play donk-ish or is this a good slowplay? I expected the button's bet, but not the c/r from BB (to which I thought "hey, the more the merrier").