What could explain this guy's weird behavior? Insecurity? Immaturity? Something else?

Anonymous
There's a guy who seemed to be pretty nice and normal. He used to/or still has a crush on me but things have progressively gotten weirder. If I'm nice to him, he wants me to leave him alone. When I leave him alone, he tries to get my attention. It doesn't seem like he knows what he wants. He also tries to make me jealous a lot. In a group, he will either pay me the most attention or ignore me and make it obvious. He acts totally fine around others. Why would this guy act two different ways around me? It's so random too.
Updates
+1 y
He's not good at conversation either.
What could explain this guy's weird behavior? Insecurity? Immaturity? Something else?
4 Opinion