This is why you don't slowplay KK

[Quercus]

What is it about 0.50/1.00 that makes people think that slowplaying high pocket pairs is a good idea?

Party Poker 0.50/1 Hold'em (9 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is Button with J/images/graemlins/heart.gif, J/images/graemlins/spade.gif.
UTG calls, UTG+1 calls, <font color="666666">1 fold</font>, MP2 calls, <font color="666666">2 folds</font>, <font color="CC3333">Hero raises</font>, <font color="666666">2 folds</font>, UTG calls, UTG+1 calls, MP2 calls.

Flop: (9.50 SB) 2/images/graemlins/diamond.gif, Q/images/graemlins/spade.gif, A/images/graemlins/diamond.gif <font color="blue">(4 players)</font>
UTG checks, UTG+1 checks, MP2 checks, <font color="CC3333">Hero bets</font>, UTG calls, UTG+1 folds, MP2 folds.

Turn: (5.75 BB) 8/images/graemlins/heart.gif <font color="blue">(2 players)</font>
UTG checks, <font color="CC3333">Hero bets</font>, UTG calls.

River: (7.75 BB) J/images/graemlins/diamond.gif <font color="blue">(2 players)</font>
UTG checks, <font color="CC3333">Hero bets</font>, <font color="CC3333">UTG raises</font>, <font color="CC3333">Hero 3-bets</font>, UTG calls.

Final Pot: 13.75 BB
<font color="green">Main Pot: 13.75 BB, between Hero and UTG.</font> &gt; <font color="white">Pot won by Hero (13.75 BB).</font>

Results in white below: <font color="white">
UTG has Kd Kc (one pair, kings).
Hero has Jh Js (three of a kind, jacks).
Outcome: Hero wins 13.75 BB. </font>

[Rhone]

I don't know if it was slowplaying so much as a bluff to try to fool you into believing he had KT, hoping to get you to fold on the river. I think he put you on Ax the whole time. I think of slowplay as when they think they have you beat all along and are trying to get you to feed the pot rather than risk you folding early.

Still, you're right that he would have been better off showing aggression early and getting some players (you?) to fold with your hand.

Rhone.