He’s finding out. Men tend to act with us the way we do with lipstick. Some you look at, put back, and move on. Some you dab a little on your hand to see if you like it. Some you like enough to take home and give it a shot. When you find one you really like, and your friends are envious, you stick with it. Sometimes you see a color you like, and ask your friend about hers.
He is checking you out on the back of his hand, sort of, and he’ll decide if you appeal enough to him to spend some real time with you.
Flirting is great fun, and a good icebreaker, but if he doesn’t see more in you, he will never think of you as anything but that flirty girl. You need to expose him to some level conversation. Let him see you have more to you than occasional witty comments.
He is older than you, sometime ask him about a teacher or class you have ahead of you. Tell him you are nervous about something being too hard for you, and what did he think of it, that kind of thing.
Whatever you do, don’t be that funny, trendy lipstick which one girl gets, passes around to all her friends, laughs about it, then ditches it. Be more real, more keepable.