walk on eggshells的意思很好理解，在蛋壳上很难让人行走，随便一走很容易就碎了，这和像走在薄冰上一样，也就是指如履薄冰，小心翼翼。

【例句】
My boss has been so tense recently that whenever I am around him, I must walk on eggshells.
我老板最近绷得很紧。所以我在他身边时，我得如履薄冰般地警惕。

I always felt as if I had to walk on eggshells around him so that I wouldn't hurt his feelings.
为了不伤害他的感情，我在他身边时，总是小心翼翼。