I think I'm going to read my best friend's conversations.
Why would you read his conversations?
He's my best friend he doesn't have to hide any secrets from me.
If your best friend wanted to share something with you he would. You should not intrude on his secrets, it is wrong to do so.
It's none of his buisness anyway and he doesn't have shit to hide from me.
It's smart to consider what you are doing, though. Even if he has no secrets, by checking his conversations, you are intruding on your friend's personal boundaries. People might see you as being untrustworthy and someone that likes to pry into other people's businesses.