He disappear but claims intense itest?

I've been dating this guy for over a month. When we're together it's great and we sped hours talking to eachother. We've met eschothers friends , etc. However lately, when I'm not with him I don't ear from him on the phone...that or I just get a text message here an there. He's 33 and I'm 28. What gives and whisked he so this?