I think I’m starting to hate my bf

So my bf has apple products. For those of you who know how iCloud works he has iMessage to send to his phone and tablet. He accuses me of currently reading his messages on one of his devices when he’s away from it, yet I’m not currently doing that. Sometimes he logs out of iMessage and randomly will log back in like a month later and I find that weird and suspicious. Like why are you randomly logging out when you use it? It is so I don’t happen to see anything? Guilty conscious? Anyway, I don’t feel comfortable with him logging out of it anymore even though I don’t read his messages. If he ever logs out of it again should I change my phone passcode as a way of getting back at him? Or is that being childish? Also, I would rather have him lock the iMessage app with a password instead of logging out cause I think logging out is just fishy. But should I even be okay with that too? If you have nothing to hide why be so private? What’s your thoughts.