KK against half the table

[Bill Smith]

Multi-table Party NL Hold 'em tourney of the $20 variety. Blinds are 150/300.

UTG raises to 1879 all-in.
UTG+1 calls 1879. His stack 13.5k.
CO calls 1879. He has about 1600 left.

Hero is in the SB with KK. He decides to flat call...

Main Pot: $7816
Flop: [ 3c, Ac, 8h ]

Big stack leads out, CO calls, I fold.