Advice.

This guy i like is coming home from college this weekend. We had a fling in the summer and still wanted to continue talking for the school year. He said he sees a future with me (and it's his senior year of college). So basically we have both been kinda busy and barely talk. He likes to go out a lot so idk what he is doing and technically he can do whatever he wants cuz i'm not his girlfriend. But the past week he's been distant. I called him out on it yesterday and he said sorry and now it's back to normal. My question is I shouldn't have sex with him this weekend right? I should see if he truly likes me right? We already had sex in the summer 1 time before he left. I just don't want him to be acting right now in hope of having someone to have sex with while he's home. What's ur advice? What should i do? What should I look out for when I see him to indicate he really does like me?