If you are treading on eggshells or are walking on eggshells, you are being extremely careful about what you say or do because you do not want to upset or offend someone. She was so easily offended, I felt as if I was treading on eggshells the whole time. Everyone was walking on eggshells around him, just not knowing what his reaction was going to be. Note: You can also say that someone is treading on eggs or is walking on eggs. Living with you is like treading on eggs.