I have done this. Twice. The second time I walked into it eyes open, not because I had done so well the previous time but because I had been unemployed for nine months and was living in my ex-wife’s guest room. For my six-month review I did a presentation on how great things were going and used a pie chart showing how I was devoting 60% of my time to one boss and the other 60% of my time to the other. (PowerPoint can do 120% pie charts if you talk to it nicely.) Two bosses = not good. (I never had a twelve-month review; I got hired away by a different department in the same company. They liked the way I did presentations.)