What would you do? #58 - Facing flop push vs. regular

I'm getting better at poker. I'm just not good enough to lay down KK pre-flop. I can do it post flop, but I should have cut my losses:

Full Tilt Poker $0.25/$0.50 No Limit Hold'em - 7 players
The Official DeucesCracked.com Hand History Converter

BTN: $60.55 - fairnbalncd, a regular with 10/8 stats over 1000's of hands
SB: $51.25
Hero (BB): $101.95
UTG: $19.50
UTG+1: $50.75
MP: $92.75
CO: $53.80

Pre Flop: ($0.75) Hero is BB with Kc Kh
4 folds, BTN raises to $1.20, 1 fold, Hero raises to $4.50, BTN requests TIME, BTN raises to $11.50, Hero calls $7
LOL - set mining with KK. The old me should be stacking off here.

Flop: ($23.25) 6s 9h 7d (2 players)
Hero checks, BTN bets $49.05 all in, Hero folds
WTF? So what are you doing here? Are you playing for stacks and hoping for a split with KK? I'm fairly certain he's not doing this with AK. The hands he could have are QQ, KK, AA. The scale is weighing far more to AA. Shame on me for calling $7 unprofitably!

Bad laydown, or am I a total donkey? Actually, don't answer that; I am a total donkey regardless.

Final Pot: $23.25
BTN wins $22.10
(Rake: $1.15)