Bill Clinton's "cake"

Slate has an article by Ben Mathis-Lilley about Bill Clinton's remarkable lack of self-awareness:

Bill Clinton sent some birthday advice to Barack Obama:

Happy birthday, @POTUS!  Hopefully when @FLOTUS isn’t looking, you can have some cake. 

It's true; sometimes you can sneak a little "cake" when your wife's not looking. But eventually she'll find out what you did. She always does.

Rico says that the 'cake' better not be named Monica...