While I was waiting for the nanny cam to arrive, there was one incident when something went missing, a book that I had ordered for my dad over Amazon and wanted to bring him the next day (at least that's what I told my bf). Of course, in the morning, the book was gone. I chose to ignore it and he reacted quite strange to it, even asked me on my way out if I had taken the book with me (why on Earth would he ask that if he didn't expect a reaction from me?). I just asked: "What book?" "The book you wanted to bring your dad." "I don't know what you're talking about." In the evening, the book was on my desk again (of course!) and I ignored it again. Two hours later, he casually walks by my desk and says: "Ah, that's the book I was talking about!" I just said: "Oh, that book." He seemed pretty angry for the rest of the evening.
Two days later, the nanny cam finally arrived. I set it up while he was at the gym and again, when he was there, placed a letter I needed for work on my desk. I wasn't surprised at all when it was gone a few hours later and re-appeared the next day. When I finally was alone at home again and could check out the nanny cam evidence, I only saw what I already knew: he took the letter while passing the desk, put it in his gym bag and put it back a few hours later. However, as soon as I saw the "evidence", I decided against confronting him. To be honest, I was scared of his reaction and had already decided to break it off as soon as possible. Also, the camera didn't show me his motive and I figured he probably wouldn't tell me anyway.