How do I tell this boy that I want him to make a commitment?

We are basically already together. We talk all the time, do everything together. He told me he'd feel really weird TALKING to another girl.. But he just got out of a relationship like a few months ago and I think he's scared to actually be in another one. So how do I tell him I want to be in a relationship with him without coming out and saying it so bluntly? We're 20.