Foxwoods - 2/4 NL AA UTG

Game is playing pretty loose. Good action after the flop. I've been there for about 40 hours straight and have a nice healthy stack.

Relevant stacks
UTG HERO: 2500
UTG+1: 1200
UTG+2: 400
MP1: 600
MP2: 250
CO: 350
Button: 850
SB: 500
BB: 400

A [img]/images/graemlins/spade.gif[/img]A [img]/images/graemlins/club.gif[/img] utg. I raise to 20. UTG+1 calls, MP1 calls, MP2 calls, CO calls, Button raises to 100.

Button has been playing normally - not getting out of line. Seems tight/passive.

What's your optimal play here? I don't really want to be HU oop against 4 other players... Results to follow