I developed early and dramatically. By age 12, I was a double D. A skinny, awkward prepubescent GIRL with big ta-ta's, are you picturing that lovely scene, lol. Anyway, would you say that it would have been appropriate for me to have had a sexy attitude at that young age, simply because I had big hooters? I'm guessing you are saying No Way!
In other words, your sexiness comes from who you are...and your shared experiences with your H...and the love that exists between you, not from a body part.
I DO get what you're saying and I can actually relate to it. This past year I spent pregnant and did not fit "society's" view of what is sexy. However, I still felt sexy and dressed as sexily as possible, despite the fact that what I was showing off was not of interest to, well, anyone! It was coming from inside me. Furthermore, it was not originating in a genital space--feeling sexy, imo, is not the same thing as feeling horny, although they frequently occur at the same time for me. Sexiness in my case is a feeling that flows up from inside me because I feel attractive and womanly and powerful. (of course, it helps if you have a partner who recognizes this and allows you to have some power, but that is another thread!:)
Anyway, I think that your size will affect things to the extent that you allow it to. I could have become fixated on my large breasts at age 12 and, coupled with the attention they received, acted promiscuously. I didn't because that is not who I was INSIDE. I was still a girl and it took a long time for me to reconcile the girl inside with the womanly body, as I'm sure all adolescents go through.
In fact, my distaste for my breasts (due to this early development and the weird reaction I got to it) has been something that stuck with me my whole life until recently. I never got a sexual thrill out of my breasts because I had spent SO much of my life downplaying them and trying to understand their attraction and seeing only flaws. In the past year or so, I have gotten re-acquainted with my breasts and even like them now! This is a huge shock to my H, who became accustomed to ignoring them..as I did. Now that I think they are sexy..and a part of me...imperfect like the rest of me...he is loving them too! It is amazing how much attention he pays them when he really didn't for the first 9 yrs we were married. Amazing how my own attitude shaped and defined his. And how a change in my own attitude has accomplished the same thing in him.
I'm sure you are thinking that you don't WANT your H to like yours any more than he already does, lol, but I think it would be completely different if you two were SHARING this, instead of coming from opposite directions.