I was in an almost identical situation a few days ago. I was a blind, the button raised, I reraised, and he pushed. I really wanted to fold, but I just don't fold KK preflop (I've done it once). I was 90% sure he had aces, but I was also 99% sure that I was wrong more than enough times to make the call correct. He turned over 55 and hit a 5 on the turn. But the point is that people will make ridiculous plays in SSNL and KK is just too good to lay down without a hell of a read.