SO just freaked out on me out of nowhere accusing me of cheating

I got a friend request from an ex today while I was at work and I clicked on it and it went away. Whatever, now my so is freaking out saying I talk to him and I get home from work later -usually 10- 15 minutes late depending on traffic and I also have an hour drive home and back everyday. Saying I talk to him on Twitter and snap chat when I don't. Does this means he's cheating? I did not cheat on him. He's making this up in his head, everything was fine and he just blew up and is telling me to leave.