Line check.. KK just give up flop?

[McRoNiX]

CO was running really nitty and put him on AK, QQ etc. I know this line is co weak but I hate firing 50-60 here as it feels like giving chips away. so this line ok?

Full Tilt Poker, $1/$2 NL Hold'em Cash Game, 5 Players
LeggoPoker.com - Hand History Converter

CO: $287.90
BTN: $198.90
Hero (SB): $248.85
BB: $200
UTG: $62.85

Pre-Flop: K[img]/images/graemlins/diamond.gif[/img] K[img]/images/graemlins/spade.gif[/img] dealt to Hero (SB)
UTG folds, <font color="red">CO raises to $7</font>, BTN calls $7, <font color="red">Hero raises to $29</font>, BB folds, CO calls $22, BTN calls $22

Flop: ($89) 4[img]/images/graemlins/diamond.gif[/img] Q[img]/images/graemlins/heart.gif[/img] A[img]/images/graemlins/diamond.gif[/img] (3 Players)
Hero checks, <font color="red">CO bets $40</font>, BTN folds, hero.. folds obv