If you didn't give him your passcode or otherwise grant permission and you didn't leave it lying around unlocked and the screen on, then it's a legit issue. Reduce anyone's temptation to take a casual glance by making sure you're already taking basic privacy measures, Judge Keith Cutler says. Change your passcode and passwords and remove notifications from your lock screen.
Read deeply and understand the nuances. 否则会被别人忽悠
Under U.S. law, people have a right to an expectation of privacy, even with close loved ones, Judge Keith Cutler explains. This means that if he hands you his phone and shows you something or leaves his screen unlocked and open where you can obviously see it, he is not expecting it to stay private. Other than that, you have to ask first. It can be frustrating to be with someone who will share a toothbrush with you but not their phone, but ultimately that's their call to make. (And it's your call to decide if this is something you can live with in a relationship.)
READ AND UNDERSTAND LOGICALLY.
”This means that if he hands you his phone and shows you something or leaves his screen unlocked and open where you can obviously see it, he is not expecting it to stay private.“