200NL: KK in tough spot multi-way pot

[Aero1441]

SB: $136.39
BB: $212.65
UTG: $200.00
UTG+1: $93.95
CO: $84.95
Hero (BTN): $195.00

Pre-Flop: K [img]/images/graemlins/diamond.gif[/img] K [img]/images/graemlins/spade.gif[/img] dealt to Hero (BTN)
UTG raises to $7.00, UTG+1 calls, CO calls, BTN raises to $33.00, SB folds, BB calls, UTG folds, UTG+1 calls, CO folds

Flop: ($114.00) 4 [img]/images/graemlins/spade.gif[/img] 3 [img]/images/graemlins/club.gif[/img] 7 [img]/images/graemlins/diamond.gif[/img] (2 Players)
BB bets $40.00, UTG+1 raises to $60.95, Hero ?

What the hell do I do here? For some reason I have a feeling that BB has Aces, what else would he coldcall here with and bet $40 on such a flop? Am I overcautious and should I just shove the flop or do I fold? Can I even fold seeing as how big the pot is already? And is my preflop raise large enough?