Going back and looking at comments between you and him, you guys seemed to get along as recently as May of this year. So something must have happened since then.
Considering both of your accounts are as old as September of last year, that's relatively recent.
You've known each other in a good way longer than you've known each other in a bad way.
Hopefully you can all get back to how you knew each other before, and just let things go, and chill out.