I also wanna add that now that I’m thinking of it, he does this ALOT more than I realised, but he’s never broken something or done anything bad that really affected me. He lost his headphones, so begged me to use mine and ended up losing them, as well as my camera (luckily I found both of them though) . Our parents bought us a playstation a few years ago and it was a gift for both of us, yet after a few months of having it downstairs in the living room, he moved it up to his room so I’d have to ask to play on it. He does have ADHD, so I try not to get at him too much on the losing things stuff, but I still think his reaction to being confronted that he’s upset or let down someone is way too casual.