@Jenniehowell
Wow, thats pretty cold. I could see myself using that if the other person were being a stalkers jerk type because chances are I would have started with simple honesty and that was being totally ignored by the other person.
But I get the impression from the OP that thats unlikely the case here. Shes just feeling a by overwhelmed or uncertain about what yo do next. Simple kind honesty should get the job done. No need to resort to being purposely unkind.
I think the Reject Hotline may have its place in extreme cases but no need to use a grenade launcher or submachine gun when a bb gun gets the job done just as well.
Just be honest and factual with him. Most guys know what it means when someone just wants to be friends. And who knows, after the sting has worn off and hes had time to get over it, he may end up turning into a friend. And we could all use one more truly caring friend in our life.