What should i do about my boyfriend?

I really like him...i think. He's really sweet. we talked for about 6 months and now we're going out.He used to always have me sit on his lap or he would sit next to me and put his arm around me. Since we've started going out he has just given me awkward hugs then walked off, he tried to kiss me but it was in front his little brother so i walked away, and we went to the park and he wouldn't sit close to me. He sat about a foot away the entire time, until I had to leave. When it was time for me to go he scooted over and put his arm around me. I was thinking wow yesterday you ignored me mostly and just watched from a distance while me and my friend were putt putting you tried to kiss me and now you just spent two hours with me talking and you wait until i have to leave to decide to act like a boyfriend. He never holds my hand, he really never talks to me a lot... i feel like i can't shut up around him because i try to get him to talk! He treats me like a princess but sometimes i feel like hes too nervous around me... what do i do?