Are we dating?

If you've only hooked up and been to one movie, I wouldn't say you're boyfriend and girlfriend, but you may be dating, only if you decide to see each other more. Dating implies going out and spending time with someone to establish a romantic relationship (usually), so far you haven't done too much of that, but if you continue to see each other then I'd say you are. Actually being in a relationship with someone means you both have feelings for each other, these feelings are normally established through dating.

For now, I wouldn't say you're dating or in a relationship. It sounds like a teenage hook up. Give it more time to develop.

sounds to me like he wants to date but does not know how to ask. this means you might have to take the initiative. no big deal though

just say something like "soooo. what are we?"

make sure you do it in person too

Well what did you say when he asked you were you dating? Maybe you weren't very clear to him in the first place. And did you ask him back in the same conversation if you were dating? That was your chance to clarify things with him. Maybe you've left him confused and he's backed off now. Not enough information here for me to answer properly though.

The only thing really is to blatantly ask him because this is between the two of you. Maybe plan a date first start some pleasant conversation then bring it up. I don't think you could a better answer than the one that this guy, himself, can give you.