$400NL. KK in 3-bet pot?

[cbboy]

UTG is 35/20/1.8.

BB is 32/18/1.42.

Both over small sample sizes. I have been playing aggro on this table, but nothing out of line. I have 3-bet each villain a few times on other tables but nothing out of line.

Party Poker, $2/$4 NL Hold'em Cash Game, 5 Players
LegoPoker Hand History Converter

UTG: $404
CO: $657.20
BTN: $421.60
Hero (SB): $418
BB: $593.40

Pre-Flop: K[img]/images/graemlins/club.gif[/img] K[img]/images/graemlins/heart.gif[/img] dealt to Hero (SB)
<font color="red">UTG raises to $12</font>, 2 folds, <font color="red">Hero raises to $48</font>, BB calls $44, UTG calls $36

Flop: ($144) 5[img]/images/graemlins/diamond.gif[/img] 3[img]/images/graemlins/diamond.gif[/img] 8[img]/images/graemlins/spade.gif[/img] (3 Players)
<font color="red">Hero bets $104</font>, <font color="red">BB raises to $545.40 and is All-In</font>, UTG calls $356 and is All-In, Hero...!?!?!?

What do I do on the flop here? Do I call?