Wearing Underwear

So I mostly always wear underwear but when I'm at home or wearing leggings that aren't see through I don't. I never thought it was a big deal until my boyfriend came along. He doesn't understand why I wouldn't wear them and he fears other me being able to "see me" but I never thought of it like that. I just know it's good to let it breathe sometimes. Anyway he's kinda upset with me about it and I just say it's my body and I'm going to do what I want especially because I'm not hurting anyone.