[~Misguided Ghosts~]

Before you go that route I would try talking to him. If he catches you trying to get into his phone or spying, he may lose a lot of trust in you, which is not the way to go. Instead maybe you can sit down with him somewhere private on a day when he is in a relatively good mood, and try to explain to him why his behavior is concerning to you? Try to use I statements such as "I feel," rather than accusing, such as "You always..."