[lil']

I'd call down.

I know that's boring, but you get to avoid the whole "do I call the re-raise on the turn or not" thing, which feels terrible, AND you get to see his hand, which I really want to see, because it's my first hand with this guy and I want to see how he plays 3 handed when I have a some showdown value. No point in making it any more expensive to get there.

But there are other things at play here too. First, a turn cr is a strong move. Check raising a lower pair here for him would be very risky. Most of the time if he's going to be aggressive with a lower pair he will do that on the flop. Second, as other people have stated, I may not want to give the impression that I am willing to fold after raising the turn for one more bet. (Edit - I forgot to add that if he's bluffing he'll just keep bluffing if you call, which others have also mentioned.)

K-9o isn't that great of a hand, but you 3 bet with it preflop (I'm not saying that was wrong, BTW), made a big pot out of it, and got cr'ed on the turn after catching a piece. Make the most of it and move on.