I do not fold KK very easily, unless I am in a situation that is close to the bubble or approaching a final table of very good prizes, why not fold, simply by the numbers. In case of your opponent having AA preflop in this circumstance you would still have an 18% chance to win and against any A in the company of strong cards like AK AQ AJ AT your chances of winning the hand are 70% and against couples like QQ JJ or TT your odds would be 81%, so why should I fold with my KK. Definitely in case of not being the scenario that initially present would go all in with this couple.