Should I give him another chance?

Okay, so there was a guy in my grade freshman year of high school (we both had crushes on each other.) It died off, and we never dated, but we always made this random plans like to build a treehouse and go kayaking together, which never happened. We're sophomores now. We both got over it, but lately he's been talking to my friends and looking at me in the hallways, but he doesn't talk, he just stares. And, I'm making serious plans with my family to build a treehouse. Should I talk to him about it and invite him to come, or should I forget about it?