I read my SO's diary.

So my bf has a secret diary where he writes all his private personal stuff. It's one of those diaries that has a lock with a little key he always hides. Tonight I saw it under the bed in a corner while I was cleaning. He was walking the dog outside so I had some time. I unlocked it and i read the most shocking things! The thing is, they were all lies! All bs! Things like"Clare (my name) really hurt me with her strap on last night. I don't know what to do. I feel like a slave." Or "i did the shopping today and bought a bunch of crackers". Which are both lies!!! First, I don't and have no interest at all in even possessing a strap on!!! I even had to look up in the Internet for what it was! (Imagine my face). And second, he never eats crackers, what the hell! And in the one who does the shopping so why did he even right that??
Ladies should I confront him or just leave it? I think he might be going crazy. I want to stress I do not have a strap on and never will!