KK Overpair to board NL25

[GeraldGiraffe]

Villain is 51/25 over about 50 hands. He seems fairly sensible though, if a little too happy calling reraises. Prior to this hand I'd reraised him like this in exactly the same position and he folded to a continuation bet on the flop.

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

SB: $22.90
BB: $32.20
UTG: $6.30
CO: $27.05
Hero (BTN): $28.45

Preflop: Hero is dealt K[img]/images/graemlins/heart.gif[/img] K[img]/images/graemlins/club.gif[/img] (5 Players)
UTG calls $0.25, <font color="red">CO raises to $1.25</font>, <font color="red">Hero raises to $4.00</font>, 3 folds, CO calls $2.75

Flop: ($8.60) 5[img]/images/graemlins/diamond.gif[/img] T[img]/images/graemlins/diamond.gif[/img] 2[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">CO bets $5.25</font>

What's a good line here? What sort of hands is he holding here most of the time? I really want to put him on something like JJ or QQ with a diamond. Any help much appreciated.

Cheers