That's why I want you to think about this now, so you don't get weird about it.
This is about him, not how he feels about you. I strongly suggest that, if and when you talk with him, be upbeat about your marriage and your sex life. It sounds like you two are the love of each other's life, so don't get hinky about him having affairs or whatever. I really think this is all about him and his insecurities about aging.

