Good idea, Lara. I wonder if it would be easier to do a story with only Perry using them and nobody else figuring it out. I could see Perry issuing himself a challenge to keep it up until someone comments on why he's only speaking in Elvis song titles, but in the end he merely sadly shakes his head about the decay of America (because nobody said anything).
Meanwhile, out of the office, everyone thinks Perry has gone bonkers because he's only speaking in Elvis song titles.
