My boyfriends legs

Me and my bf gave been together a year and we've never had sex nor have I ever seen above his knees... He's just never let me. I've never understood why I've never seen my boyfriend naked or even above his knees.... We had a talk about it. I just wanted to know why and told him he could trust me. I honestly thought he self harmed.... But he pulled his pants off and on his though he has initials.... He was branded... He didn't so why it was there and I didn't ask. We just sat in silence and I held his hand... Now that we've taken this step... What should be my next step?