WHY doesn't he approach me again!?

since you acted so cold to him, he might think you're not interested. i know you smiled at him after that but some guys are stupid and you have to be patient rather than getting mad that it took them too long to talk to you. i've learned from experience that sometimes you need to be patient. like i said, you acted cold to him so he might think you're not interested. i'd talk to him and tell him what really happened.