Now, Andrea, that WOULD be telling wouldn't it?
I think the worst thing I've ever done was to shred a letter concerning a formal complaint against a member of my organisation. I realised my mistake whilst I was merrily shredding a whole heap of documents. Fortunately, I managed to rescue and repair the letter. Thank goodness for the reverse button and sellotape. As for Bossie - I explained what had happened. She just laughted, although the implications for my organisation if we had lost that letter might have been serious. Now I check my documents-to-shred heap every time, needless to say.
No matter what I had done, I think I would always volunteer information rather than be "found out". It rather depends on your relationship with Bossie and Bossie's general temperament, but I think it is very disarming when someone says "I have done xyz and I am sorry. What can we do to put it right?"
Raindance