Guys and relationships.

So I've been seeing this guy and we recently talked about where we stood. He said he wasn't wanting to settle down yet. So I said it was fine, I wasn't really concerned one way or the other. We are both in college, so there is more things than focusing on a relationship right now. We are not looking to have a child, but we are intimate with each other. He came over the other night for the first time since we discussed not being tied down to each other and asked me if I had been seeing anyone else, he asked for my phone password and asked the names of anyone I had been dating. If he is not looking for a relationship why would he suddenly prosecute me? I told him I wasn't discussing that with him and I don't get why he would care. I don't ask who he sees outside of me, because he made it clear we were young and needed to finish college and I'm also pretty secure in myself. Is he playing the double standard on me?