[NL25] KK on low flop against tight nit

[Aero1441]

Party Poker - No Limit Hold'em Cash Game - $0.10/$0.25 Blinds - 5 Players - (LegoPoker HH Converter)

Hero (SB): $46.16
BB: $43.30
UTG: $10.77
CO: $38.20
BTN: $23.19

Reads: <font color="blue">I have been playing for a while against this tight nit. He was playing pretty well and we both almost doubled our stack. His stats:
VPIP$ 12.5
PFR 11.25
Total AF: 2.4

I raise a lot of hands and make standard bets on the flop, so my cbet on the flop can pretty much mean anything, from a set to overcards... and he knows that.</font>

Preflop: Hero is dealt K[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/club.gif[/img] (5 Players)
3 folds, <font color="red">Hero raises to $1.00</font>, BB calls $0.75

Flop: ($2) 4[img]/images/graemlins/club.gif[/img] 7[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/heart.gif[/img] (2 Players)
<font color="red">Hero bets $1.25</font>, <font color="red">BB raises to $3.50</font>, Hero calls $2.25

Turn: ($9) Q[img]/images/graemlins/spade.gif[/img] (2 Players)
Hero checks, <font color="red">BB bets $8.55</font>, Hero calls $8.55

River: ($26.10) 8[img]/images/graemlins/club.gif[/img] (2 Players)
Hero checks, <font color="red">BB bets $24.80</font>, Hero folds

Pot Size: $50.90

I would really appreciate some insight, cause I just can't get this one figured out. The funny thing was that he used the "bet pot" button on the turn and the river. I know this because when I checked he instantly bet pot against me.