Just a bad beat. You have to call with KK and roll the dice. If you double up you are in position to make a run to the final table and if you lose you are a crippled.
On the button in particular, he could be making a move with a dominated hand like 77 or 88. It is likely that he has AK since people want to get it all in to see all the cards with AK.
Later in tournaments as you get closer to the final table, I have folded JJ or QQ to a tight players reraise because I did not want to race my way out (or worse). But I don't think there are many, if any, good times to fold KK in a tournament.
Weirdrash
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