2 pair vs. 2 loose opponents
 

MP1 is LAG. Button seems loose-passive but I'm not really sure yet.

Party Poker 0.50/1 Hold'em (9 handed) converter

Preflop: Hero is BB with 4[img]/images/graemlins/club.gif[/img], 9[img]/images/graemlins/heart.gif[/img]. CO posts a blind of $0.50.
UTG folds, UTG+1 folds, MP1 calls, MP2 folds, MP3 folds, CO (poster) checks, Button calls, SB completes, Hero checks.

Flop: (5 SB) 4[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/diamond.gif[/img] <font color="blue">(5 players)</font>
SB checks, <font color="CC3333">Hero bets</font>, <font color="CC3333">MP1 raises</font>, CO folds, Button calls, SB folds, <font color="CC3333">Hero 3-bets</font>, <font color="CC3333">MP1 caps</font>, Button calls, Hero calls.

Turn: (8.50 BB) K[img]/images/graemlins/spade.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">Hero bets</font>, <font color="CC3333">MP1 raises</font>, <font color="CC3333">Button 3-bets</font>, Hero calls, MP1 calls.

River: (17.50 BB) A[img]/images/graemlins/club.gif[/img] <font color="blue">(3 players)</font>
Hero checks, <font color="CC3333">MP1 bets</font>, Button calls, Hero calls.

Final Pot: 20.50 BB

I felt fairly certain I had MP1 beat, but should I have mucked this when Button woke up on the turn?

Re: 2 pair vs. 2 loose opponents
 

This is a tough spot. His play -- calling 2 cold twice on the flop and then three-betting the turn, reeks mightily of a set, but could also be Kxd. (I discount AKd or K3d since the former would likely have been raised preflop, while the latter would have been raised on the flop.)

The problem is the presence of the LAG means that you don't know how expensive it will be to see it to the end, and you could be drawing dead or to one out.

That having been said, it takes more than a 3-bet in this spot to convince me that the button has a set, so I'm likely staying in. Having made that decision, I favor raising over calling and check-calling one bet on the river.