How can I tell if he wants to be more than friends?

Help! I'm really into a guy who is younger than I am. I'm a graduate student and he's an undergrad, but I really like spending time with him. I can't tell if he's not interested or if he's just insecure because of the age/status difference. He texts me all the time and tells me things like I brighten his day. He will invite me to group events, but he has never tried to spend alone time with me outside of the school pub. He displays the 'classic' signs of interest when we're together such as joking, flirting, sitting near me, staring at me, touching me when he talks to me, and even looking me up and down when I'm standing. I want to make a move on him, but I don't want him to reject me. Ugh! What should I do?