Bear with me. 
We have a spare room. It is kept locked. There are currently dc's Christmas presents hidden in there. The key is kept on top of the door frame. The frame stands slightly proud of the wall and the key can fall behind the frame, to sit on a ledge, but is easily flicked out again.
(I'm getting there.) I put the key back on the other end of the doorframe to where dh usually puts it. I see no difference. Except dh has gone looking for it, run his hand along to find it and obviously knocked it right down the side of the doorframe. Where it definitely cannot be retrieved without removing the side of the doorframe. Which he will do at some point because it shouldn't really be like it is.
Are you still with me? Oh thank you. Dh has gone apeshit at me because the key has vanished. He says he didn't knock it down. I say he must have done. Apparently it is all my fault for not putting it back in exactly the same place. I think he must take some of the blame.
I realise, in the grand scheme of things, that it doesn't really matter and no one would otherwise give a shiny shit. However he has had a massive go at me over it and I am not happy. I accept I moved it but he must have knocked it down and I am not prepared to be shouted at for it. We do have the spare key.
Which he wouldn't let me have. In case I somehow lose that one. I now can't get in to the spare room. Where all the presents are.
Has anybody made it this far? Is he being a knob or am I? I think my marriage depends on it tonight! 