Nix Nick?

The next night I had dinner with Nick. We walked from his place to a great sushi place. The food was fantastic, the conversation less so. This was our fourth date- shouldn't it be something more than polite conversation? Why do our dates continue to feel like I'm entertaining an out-of-town cousin? I'd like to feel past small talk by this point.

Back on the couch at his, I decided it was time to upset the apple cart.
J: "So Nick, you seem like you are a little hard to get to know."
N: "I'd say that's accurate."
J: "Okaaaay. Well why is that?"
N: "I don't know- maybe you should ask my shrink."

And I'm out. He refused to open up, or to enlighten me about his inability to open up. This conversation also included him questioning my motives for moving to San Francisco- rather suspiciously. Are you kidding me? Does he think I am on the lam? Only someone who has something to hide believes that about others. After I accidentally made out with him (oops! and it was actually fun- is that bad?) I headed home. In the light of day, I decided that I had to trust my instincts about Nick and stop seeing him.

He went out of town for the weekend, and I didn't hear from him before he left. Maybe our lack of a spark was obvious, and he was feeling the same way. Was it possible that I was going to get out of this with him just never calling me again? Not so much. Over the weekend I got the text that every girl wants... from the right guy. From the wrong guy, it just inspires dread. "Miss you :)". Oh dear. I didn't respond. I know! But I figured the only proper response is "Miss you too", right? So I did nothing. I still haven't heard from him. I feel bad. Should I email him, or just let sleeping dogs lie?