My Bf keeps his clothes in during sex

I’ve been with my boyfriend for over 2 years now: since I was 15 and he was 16 (he’s 19 and I’m almost 18 now). We’ve been having sex for almost the amount of time we’ve been dating, too, but, he’s never gotten naked with me before. He is a little chubby, but I don’t mind it at all. I fell as though he’s just insecure and doesn’t want to show me (even though I wouldn’t care at all). I don’t plan on confronting him about it until later in my relationship, because it’s really not my business and I don’t mind. Does anyone else’s *longterm* bf do this?