I said something mean to my project assistant this morning (well, not really - she was proofing something from another attorney and I had her convinced for a few minutes that "rev'g" meant "reversed by government order" rather than just being a typo for "rev'd.") After the inevitable breaking up in laughter, I gave her my old, much-hated copy of the Blue Book from law school and told her to use it until the firm ordered new editions for both of us.
Some hours later, she comes up to me and says "I have your new copy of the Blue Book, but I'm not giving it to you until you take back the mean thing you said this morning." To which my response was yet more laughter. The best threat you can come up with is withholding a new Blue Book? It is to snort derisively.