Is he really into me or is it just casual?

hey! so i've been hooking up with my friend at parties every weekend for the past month. last weekend was my birthday party and he asked me if i wanted to date, so i guess we're dating. we hangout fairly regularly. the other day i was at his house and he invited me to stay for dinner, but i couldn't. i guess he's talked to his family about me a few times. but i'm just wondering if he's actually into me, because he never makes a move physically when we're sober. except he did put his arm around me once when we were alone, and only holds my hand when we're alone. so is he just shy or not into pda, or does he want it to be just a casual partying hook up thing? what do you think yahoo answers community!?