Can I fold this?

[jr4284]

Villain and I have played together a semi large sample, so I have a pretty good read on him.

He runs at 40/30/1.85, but I *never* see him get out of line in big pots. The only large pots he loses are the straight vs. boat-on-river type hands. Also, he 3-bets 99+ here PF.

On to the hand.

PokerStars 2/4 Hold'em (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

Preflop: Hero is BB with 5[img]/images/graemlins/spade.gif[/img], 3[img]/images/graemlins/spade.gif[/img].
<font color="#CC3333">UTG raises</font>, MP calls, CO calls, <font color="#666666">2 folds</font>, Hero calls.

Flop: (8.50 SB) Q[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, <font color="#CC3333">UTG bets</font>, MP calls, <font color="#CC3333">CO raises</font>, Hero calls, UTG calls, MP calls.
(Should I 3-bet? I don't want to fold out the other two guys in the hand, but they'll likely call along with me.)

Turn: (8.25 BB) 5[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, UTG checks, MP checks, <font color="#CC3333">CO bets</font>, Hero calls, UTG calls, MP calls.

River: (12.25 BB) 5[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, UTG folds, MP calls, <font color="#CC3333">CO raises</font>, Hero ???

I know the pot is huge, but I can't see him turning over anything but a boat. I don't know if I can fold it in this big of a pot.

While I'm at it, my WTSD is 38, and I feel that I'm making some loose calls (much looser than this hand) where I'm fairly certain I'm beat. Should I try to get the number down, say, to 34/35, or just be an agressive showdown monkey that plays position?