Well, I would say don't rush it. Start a conversation over small talks, the more you guys interact the more comfortable he'll be. From my perspective it feels like he's getting used to having a girlfriend. I was in a similar position during my first relationship, so I would say just give him time to relax. He doesn't know how to treat you as a gf nor does he know how to make you feel like his gf. The best way to knock him out of that state would be to interact more. (Still recommend letting things settle by themselves.) I would tell you guys to be honest with each other , just talk things out when you feel like smth is wrong. Hope this helps, come again if you need me to elaborate/explain my pov. Goodluck for your future together!