I agree with Open Eyes. Just set him down, tell him how you feel. No need to necessarily SWAT kick the proverbial door here, just set a foot in it and see how it goes. I would think that if he's affectionate with you like you say and that he's comfortable being referred to with you as a bf/gf couple, he's just waiting for you to ask.

He sounds like a great guy from what you say. I wish you both the very best.