[walk|be] on eggshells

to be extra cautious about how one behaves or talks to avoid making someone offended or upset

The idiom "walk on eggshells" has its origins in the idea that eggshells are delicate and can easily break under pressure. It is used to describe a situation in which someone is being extremely cautious, tiptoeing, or speaking carefully to avoid upsetting someone or causing a problem.

After their argument, they were walking on eggshells around each other, afraid to bring up the topic again.
In a tense office environment, employees often feel like they have to walk on eggshells to avoid conflict with their superiors.
When discussing sensitive topics with her friend, she knew she had to walk on eggshells to avoid hurting their feelings.
The new teacher felt like she was walking on eggshells in the classroom, trying to maintain discipline without being too strict.
In a family with a history of heated arguments, everyone learned to walk on eggshells to keep the peace during gatherings.