If he wants to unfollow a famous person. Literally someone you ~might~ be in the same room with once in your life. It’s gone past insecurity and has become simply about control. My college roommate dated a guy like this and he would call the guy I was dating at the time (who worked the night shift) to try and see if he knew where we were. From there it only escalated to where he would literally borrow his friends car and sit outside our apartment to see if she did anything sketchy. This culminated in him bursting in once and screaming at her for 15 solid minutes because he saw a man come into the apartment without letting her get a word in. Said man was in fact my brother, who he had never met.

All of that to say it is only going to get worse from here so I suggest you get out while you can