I wouldn't advise that you do this in exactly those words. Divorcing your sexuality from your love and affection, even in reference to past events, is first of all, not entirely honest (though maybe it's sincerely stated and you're just not being entirely honest with yourself) and second of all, it cheapens and debases all your future sexuality into something that is separable from your love and affection.

Of course, sexuality CAN be separated from love and affection, very easily, and that's why the sort of person all of us want to meet when we go looking for a partner is someone who does not practice this separation. Your YF deserves the integrated, authentic, non-schismatic, non-self-contradictory you. (Too academic? If he feels much the same way as you do, he deserves the you who gets a hard on for the boy he truly loves.)

The essence of gay-positive christianity is to subjugate everything to love and not to separate your sexuality from it. I was once asked by a friend in the MCC (majority-gay) church if I didn't think it was ok to go to things like the gay baths for "just sex." To me, this seemed to indicate he didn't really get the hang of what the church was all about, since Christianity to me urges people to go beyond "just sex."

On the other hand, maybe I am just a bit confused about your verbiage. If all you plan to do is assure him that you still love him even if there is no sexual aspect to your relationship, and that your affection earlier on was totally genuine and was not just based on a desire for sex, then that's great.

Just be careful NOT to say it in a way that makes it sound like any sex you have with him will be for sexual purposes only. It should be clear that if it happens, it will be become another dimension of the love and affection you feel for him.