A stereotypical "nice guy"...is going to need A LOT of reassurance from you. His fear of rejection is so strong that he feels that, from his perspective, there is next-to-zero risk of you saying "no".
So you're gonna have to very obviously and blatantly flirt with him. You can go as far as to say "so when are you going to ask me out?"
This is the ONLY method to probe him into asking YOU out.
Otherwise you're gonna have to ask him yourself.
Hopefully I helped you out.
Why don't you stop playing the waiting game, and ask him out yourself. If you want in something lin life, go after it. At least you'll get immediate results, instead of waiting for things to come to you--and that's if they do.