Let's define our terms first, then get to the business of answering your question.
Hot: Used here to describe sexuality, passion, and emotional expression.
I just wanted to put that out there to frame the conversation, so that we don't get angry comments that say things like "You think you're too beautiful? Go to hell!"
Clearly, when you say "hot," you're talking about sexuality and any outwards displays of sexuality. Perhaps it is how you dress, how you talk to him and his friends, and, of course, how you are in the bedroom.
I wouldn't want you to tone down any of what makes you who you are. Your boyfriend is attracted to you because of who you are, not who you might be if you dress more conservatively or have less fun in bed. You're not going to lose his respect. He likes you for who you are.
That said, if you want to talk to him about it, talk to him about it. Ask him why he mentions your sexuality so much - is it because he loves those aspects of your personality, or is it because he's still getting used to them? If you have any concerns, that conversation with allay them.
Keep being who you are. All people, as a rule, should be too hot.