I play 1/2 NL live far more than any other game.

Recently, 2 hands have made me consider folding KK preflop.

Hand 1.

MP, raise in front of me to 12, I pop it to 40, he raises to 80.

Here, I'm 90% sure he has AA (player is tight, and mostly passive).

I call, flop all unders, he's all in, I call and I was right. Cheap lesson since he only had about 30 after the preflop action.

Hand 2.

I'm UTG, raise to 12 UTG +1 calls, UTG+2 is all in for $107 total.

Here, my instincts say AA again, but I'm much less sure, since I think JJ, QQ make this play to shut out AK. I call AND UTG+1 calls.

Again he had AA. (irrelevant side note: I spiked a K on that one)

So, at 1/2 should I start laying down KK to save money when I'm reasonably sure my opponent has AA, or is it +EV to call due to a lot of bad play at lower stakes?