Ke t your mind go there first, fantasise about you and he in a realistic scenario and make it as detailed and explicit in your mind as you can....if the detail is there and your body responds then you've just gotta check your moral compass - but if it ain't serving your needs I suggest you turf it out the window and tuck in.....if its just the CONCEPT that gets your juices flowing then stick to explicit inc porn and use your imagination to replace the characters when the find the clips that trigger you....or stalk him and flirt with him like any other boy and see where HE is actually placed.
Or if you are more a person of action and don't like too much pondering wake him up with a blow-job of a morning, I'd say that's a reasonably transparent and decisive move....oh there is magic everywhere....