Guy Advice?

I NEED your advice.

So I’m talking to a guy, we’ve been talking for about 3 weeks now. Problem is, I get attached easily which obviously isn’t good. I never text him first, I just don’t wanna come across as weird or clingy. My question is, how do I make him get the impression that I’m not wanting to get too close to him without telling him? I don’t want to play games and purposely not text him back within a certain amount of minutes. Basically what I’m asking is, how do I play it cool?