decisions with KK - bad push or bad beat?

[Smoove]

I don't consider myself a good player but I do think I'm certainly better than a good number of the players on Party. Looking for advice on this hand.

Party Poker No-Limit Hold'em, $0.50 BB (8 handed)

MP1 ($17)
MP2 ($14.45)
CO ($69.45)
Button ($43.83)
SB ($54.48)
BB ($18.90)
Hero ($18.75)
UTG+1 ($24.50)

Preflop: Hero is UTG with K[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="CC3333">Hero raises to $1</font>, <font color="CC3333">UTG+1 raises to $3</font>, MP1 folds, MP2 folds, CO calls $3, Button folds, SB folds, BB folds, Hero calls $2.

Flop: ($9.75) J[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/diamond.gif[/img] <font color="blue">(3 players)</font>
Hero checks, <font color="CC3333">UTG+1 bets $3</font>, CO calls $3, Hero calls $3.

Turn: ($18.75) Q[img]/images/graemlins/club.gif[/img] <font color="blue">(3 players)</font>
Hero checks, <font color="CC3333">UTG+1 bets $5</font>, CO folds, <font color="CC3333">Hero raises to $12.75 (All-In)</font>, UTG+1 calls $7.75.

River: ($44.25) J[img]/images/graemlins/club.gif[/img] <font color="blue">(2 players, 1 all-in)</font>

Final Pot: $44.25

Results in white below: <font color="white">
Hero shows Kh Kc (two pair, kings and queens).
UTG+1 shows Jh Kd (full house, jacks full of queens).
Outcome: UTG+1 wins $44.25. </font>

I figured he would play any queen, AA, or JJ softer than he did. So he was either bluffing or he had a single jack. As it turns out CO was holding AJ meaning this was a 1-out beauty...but should I have been out of the pot?