Preflop, you can't put him on much. He only had to risk $3 to win $10, giving him pretty good odds. He could be playing a small pocket pair or any number of drawing hands. He could also be slowplaying AA from early position, especially if there are aggressive players at the table giving him a reasonable expectation to get a chance to reraise to isolate. Since it folded back around to him, a smooth call would be reasonable.

On the flop, the betting order appears to have changed. Did the opponent check-raise? That changes the scenario a bit.

If he's stone-cold bluffing, it's a terrible bluff ($90 to win $18 needs to work about 83% of the time to break even). I would rule out the bluff until I knew more about the opponent.

To me, it appears that your opponent has an overpair or caught part of the flop and wants to take down the pot on the flop. Let's just say it's about 50-50 that he has either two pair, a set or AA vs. AQ, KQ, or QJ.

In that scenario, you have 2 outs when he's ahead, he has 5 outs 66% of the time when you're ahead and 2 outs the other 33% of the time. I think that nets out to about -4% (he wins 16% the 50% of the time you're ahead, you win 8% the 50% of the time he's ahead), putting you at about 46% win rate. You'd only have to put in $90 to win $108, which is slightly +EV in that scenario.

Bottom line, Q83r is a really friendly flop to KK. If you know you're not gonna sac up and play your cowboys on a flop like that, you need to raise more preflop to get a better idea of where you are. A bigger preflop raise would allow you to eliminate Q8, 33, and maybe even 88. Also, if $90 seems like too much to call, you need to pick a lower limit.

(Disclaimer: "you" is not intended to refer to any poster. I realize this is a hypothetical situation.)