Should i let him back in?

In jr high and freshman yr there was a guy I really liked and he really liked me. We never dated, but we made up stupid plans like building a treehouse and kayaking and having picnics. None of them happened. Lately, he's been going out of his way to talk to my friends (he knows that if he talks to them, my friends will gush to me. He's really gorgeous) and he stares at me in the halls. Im still falling back and forth as to whether or not i like him. I'm makin plans to build a treehouse now, two years later. Should I invite him?