How do you know when a guy is just using you?

I think a guy I am hooking up with is just using me for sex. We text and talk often but he only wants to hang out with me when he's horny. I know he's horny because he starts sending the 'sweet' texts like, 'come lay with me' or 'i want you to be here with me' stuff like that. But then we also talk about regular things and act like friends, and even like were dating. We have hung out and not had sex but usually we do... So is he just using me or what?