How do I talk to this guy about...?

This is much simpler than you think. I sounds like you two talk about just about everything, so have that dead serious moment just once. You don't need scriptures or quotes, just simply tell him what you feel. If he cares then he will listen. He does love you he will completely accept that this is a vital stipulation for you and be willing to wait. If he is not willing to wait for you to be ready then he is not "the one" and there was no sex to get in the way of a strong friendship