How do I tell a boy that I want to stay friends...and not anymore?

I had gone to homecoming with him earlier this year, not really thinking he wished for more than friendship… (Ridiculous idea right?!)

Well..now after school events, he would walk me home and we would awkwardly hug and then he would leave…

So before winter break, I told him directly, that I wanted to stay friends and that I wasn’t looking for a relationship just yet. Well…after I told him that, he said “for now right?”... I pretended to ignore that, and got saved by the school bell…literally…

And now… a few months later, he sits super close to me (closer than he does to any other girl), and tries to walk me to my next class…

AGHHHH. I like him as a friend…but I dont want it to go anymore!! What do I say??!