Well if we were friends, I would ask, in the most appropriate manner:
"To Death, my good friend,
In all of my years of life, you have been my most cherished companion. You were the Han Solo to my Chewbacca, the Christopher Lee to my Peter Cushing, the Winnie the Pooh to my Piglet. I have one request, that I be allowed to depart from this world when you do. I know this is a stretch of our friendship, and I understand if this is impossible for you to grant. Let me say this in the words of the great author, Mark Twain, "Now here are these two unaccountable freaks; they came in together, they must go out together".
TL
R I ask that I die when Death dies as well