This happened to me a few days ago too. this lil fishy player overraised preflop but i had caught him doing this with a-10 earlier. This time i Had KK, i re-raised 2x and he pushed the rest of his Giant stack INSTANTLY. I was the only other big stack and i was 90% sure he had it, but come on, he overraised preflop with a-10 tenhanded!

Your situation was 6max right? their's no way in hell im getting away from KK 6handed unless villain is the rockest rock to ever rock. Even then, i'd probably still crying call it unless i was on my absolute "A" game that day. But i don't know, i dont play 6max much, so i haven't run into it.

Anyway, insta-call. its 6max for god's sake!