Massive nit folds KK on flop against spazzy unknown

Only a couple of hands on villain, but after the action in the hand, we probably don't really need any hands to mark him in an interesting shade of spaz blue.

I mean, I can make an argument for calling because he's obviously spazzy, but I don't know how much of his preflop spazzing range then shoves the flop.

With the sizing, I need 36% equity, and I have 44% against AA-QQ, JJ. The problem is, I'm not sure that's conservative enough - with the preflop action, he could probably show up with 77 and 22 here too, but then if he could show up with 77/22, he can probably also shove the flop with 89o or 6h4h.

On reflection, I actually kind of wish I'd called, if only to make notes on him if I got coolered, but since his 3bet is so small, after I 4bet him, it's more like a 3bet pot size, so although I wouldn't be folding if the flop pot here had been like 40bb, I don't mind it _too_ much.

Perhaps I'm just a big nit, but I thought I'd see what everyone else thought of the fold.

Poker Stars, $0.05/$0.10 No Limit Hold'em Cash, 6 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

BTN: $10.17 (101.7 bb)
Hero (SB): $10 (100 bb)
BB: $14.49 (144.9 bb)
UTG: $6.97 (69.7 bb)
MP: $25 (250 bb)
CO: $12.64 (126.4 bb)

Preflop: Hero is SB with K K
UTG raises to $0.20, MP folds, CO raises to $0.49, BTN folds, Hero raises to $1, 2 folds, CO calls $0.51

Flop: ($2.30) 7 J 2 (2 players)
Hero bets $1.70, CO raises to $11.64 and is all-in, Hero folds