Who Walking on Eggshells?

to be very careful not to offend or upset someone: If you're sick you don't want people treating you differently, and you really don't want people walking on eggshells around you.

Why do we say walking on eggshells?

To walk on eggshells originates clearly from the imagery. Eggshells are very fragile so it would take great care to walk on them without smashing them. It's alike to walking on thin ice in reality.

Is the expression walking on eggs or walking on eggshells?

The OED defines the phrase “walk on eggshells” and its variants as meaning “to be extremely cautious in one's actions or words, esp. so as to avoid offending or angering others.” ... In another citation, Ernest Rhys wrote in his Lyric Poetry (1913): “To speak of these things is to walk on egg-shells.”