middle set in a huge multiway pot

[private joker]

2/5 NL live. I have 500, UTG has about 200, button has us way covered. No reads on either player.

4 players limp (lol) and the button raises to 20 (LOL). SB folds, I call in the BB with 88 (yes?). All other limpers call, 6 to the flop for 120.

Flop comes A[img]/images/graemlins/club.gif[/img]8[img]/images/graemlins/club.gif[/img]3[img]/images/graemlins/club.gif[/img].

I lead out (?) for 120 (??). UTG shoves for his last 180 or so. Folded around to button, who thinks, looks at my stack, and shoves. I have 360 left, the main pot has 480, and the side pot has 360 obviously. My play is to...

Also, if you call, do you also call with 33? If you fold, then how would you play the flop differently to avoid this scenario?