The expression when I was growing up, was “walking on eggs”  i.e. how one had to be careful around a touchy person. “Whenever I talk to her, I feel like I have to walk on eggs.”  Meaning you have to be careful not to break the eggs.   How it got changed to “walking on eggshells” I’ll never understand. If you walk on eggshells, the eggs are already broken.  Think about the expression before you use it.  Eggshells is wrong. Eggs is right.  Sigh.  There’s a book out with the title Walking On Eggshells.  Sorry Charly, that’s not correct.  Think about it. But as my daughter said to me:  Chill mom, you can’t fix everything.