Generally speaking, If he's check-raising instead of slow-playing, he is saying he has something worth playing. If he check-raises twice I'm going to tend to think he's full of shit. Why check-raise on the turn. If you had a hand worth check-raising the flop, you're going to want to get the money in on the turn and eliminate the risk of giving a free card that could beat you. If he check-raises you twice, there's a good chance you're not going to let the hand go anyway. If you're in a position where you are check-raised twice, you are probably pot-committed. If it's heads up, I am going to pay him off even if he does hold a hand better than mine. That's valuable information you are paying for. I might lose that buy-in, but heads up you have to be thinking about and making moves and gaining information for future hands.
I am going to want to know what situations would cause that player to make a play like that, especially if there's any kind of chance we will bump heads at a later date once again.