Help with Kings

[arfsananto]

Big pairs when they don't improve are killing me. Please tell me what I did wrong on this one.

Party 2/4, 4th hand, full table. Party Poker 2/4 Hold'em (8 handed) converter

Preflop: Hero is SB with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img].
<font color="CC3333">UTG raises</font>, UTG+1 folds, MP1 folds, MP2 folds, CO folds, Button folds, <font color="CC3333">Hero 3-bets</font>, BB calls, UTG calls.

Flop: (9 SB) 2[img]/images/graemlins/spade.gif[/img], 5[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/club.gif[/img] <font color="blue">(3 players) </font>
<font color="CC3333">Hero bets</font>, BB calls, UTG calls.

Turn: (6 BB) 7[img]/images/graemlins/diamond.gif[/img] <font color="blue">(3 players) </font>
<font color="CC3333">Hero bets</font>, BB calls, UTG calls.

River: (9 BB) J[img]/images/graemlins/diamond.gif[/img] <font color="blue">(3 players) </font>
Hero checks, <font color="CC3333">BB bets</font>, UTG folds, Hero calls.

Final Pot: 11 BB
<font color="#990066">Main Pot: 11 BB, between Hero and BB.</font> &gt; <font color="white">Pot won by BB (11 BB).</font>

Results in white below: <font color="white">
BB shows 7c Js (two pair, jacks and sevens).
Hero shows Kd Ks (one pair, kings).
Outcome: BB wins 11 BB. </font>

Thanks for all input