NL25SH KK overpair gets donked on the flop

[stever1k]

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

SB ($25.35)
BB ($13.10)
UTG ($26.50)
Hero ($25)
CO ($42.55)
Button ($5.60)

Preflop: Hero is MP with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $1</font>, CO calls $1, <font color="#666666">2 folds</font>, BB calls $0.75.

Flop: ($3.10) 4[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets $2.25</font>, <font color="#CC3333">Hero raises to $6.25</font>, CO folds, <font color="#CC3333">BB raises to $12.1</font>, Hero calls $5.85.

Turn: ($27.30) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>

River: ($27.30) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot: $27.30

Should do not like calling here, because of my bad position in between, I tried to force out CO.

Both players are unknown to me.