you did the right thing bro. he sounds like one of those guys who still can't let shit in middle school or high school go. He probably still talks about the glory days in high school while everyone else is getting ahead. Fuck him, he's a loser. You probably pissed him off even more by not saying anything and just walking away
Or, you can do what A1R3K said and smack him in the ballz when he's doing bench press. I cracked up when I read that. LOL You could always wait till he's doing squats and kick him behind his knee's. That would teach him a lesson. lmao