Do you think it’s wrong if your SO gets livid over you being on social media?

My SO flips out if I get on social media and even worse got upset because my guy friend commented on something. I mean he got so upset he started crying. He says I betrayed him because I did something he hates behind his back ( I logged on and browsed through Instagram) he won’t forgive me and keeps throwing it in my face . This happened six months ago and again recently. What is the big fuckin deal. He says I’m not who he thought I was because I went on it without him knowing. I’m literally not doing anything inappropriate!!