Assualt Charges

Ok im not much of a legal guy so you all will have to put this a bit simpler for me.

Basicaly what happened is me and some friends were playing with an airsoft gun and shooting at each other. A guy who we dont like so much comes down to the park and we take about 10 shots at him at which point he calls the cops. The cops come down and take my gun for evidence take pictures of a bruise he got from the airsoft pellet on his back and drive me home. The dude who came down to the park dosnt press charges, but now, about 2 months later. He is constantly being an ass and talking about how he has a leash on me and can throw me in prison. How long can he theoreticaly press charges after the fact? I know the cop said something about getting my airsoft gun back if he decided not to press charges or something, but my parents dont want to get it back. If this is being held indeffinatly can he press charges anytime afterward?

I live in the state of Texas in travis county if that changes anything. Any posts would be nice, I tried looking on google but couldnt find anything.

He can press charges after-the-fact, although the longer he waits the less likely it is that a prosecutor will authorize a charge.