He doesn’t touch me

When my bf and I r in public he never holds my hand or puts his arm around me. We’ve been together a year (I’m 16 he’s 18) and the only time he actually shows affection is when we r having sex. I hate that he never does it when we r doing normal actives. Also i would try to hold his hand but since he doesn’t do it i assume he doesn’t want to. It’s making me feel like he’s ashamed to show me off or something. What should I do?