DTR???

Is it wrong/bad/worth it to define the relationship when the relationship is in a good place?? We've been dating/talking for four, almost five months. We both make equal effort to see each other. We FaceTime every night and text every day. I went to the Air Force ball as his date last Friday and we're discussing him joining my family for thanksgiving. He's met my dad and I'll meet his mom over thanksgiving if he comes. He's introduced me to all his closest friends including coworkers & his supervisor sends him texts asking about me. We have agreed that neither of us is seeing other people.

My problem is that we haven't had the talk of "what are we". We say that we're serious but we don't really have the title of boyfriend and girlfriend. I want to talk to him about it but I always chicken out bc I feel selfish. With everything else as great as it is, why do I feel the need to have this dumb title?? Should I let it go and just enjoy the relationship for what it is or go ahead and have the talk??