Backstory: I've been staying at a friends for a week taking care of his pets while he goes on vacation. I logged into my PSN account on his PS4 and played some games, got some trophies and stuff. So... do I just delete my account from the PS4 user selection now that I'm done or do I need to do anything specific to un sync my account from his PS4?Just making sure. I'm only staying at his place for another day so I want to get my account of his PS4 before I leave.

If you did not set his PS4 as the "primary PS4" on your account you should be good after just deleting your account. If you did activate it as your "primary PS4" then go to settings/PSN/activate as primary PS4 and select to deactivate it. Otherwise you have to do it from the internet which you can only do every 6 months, so dont unless you have to.

Thanks @lego_my_eggo ! I did not set my account as the primary. going to go delete my profile right now!

BUT FIRST....