Walking on Eggshells

When you're Walking on Eggshells, you are treating someone very carefully and gently.  Likely, this person is either in a delicate emotional condition, or you're afraid that they will get very angry.

 

So, you proceed as if you were walking on eggshells without breaking them!  For example, you just heard that your friend lost their job, and you know that they are up a creek without a paddle.  So, you walk on eggshells when you are around them, so they won't be more upset.

Tomorrow, we'll be talking about people who are very Down to Earth.