Walking on eggshells

ɹʌtuː lvθɹiː beɪətuː bɪŋwɒn ɹʌtuː luːθɹiː batuːəʊ bɪwɒŋŋ

In Chinese 如履薄冰 (rú lǚ báo bīng)

This idiom means to tread on thin ice, implying extreme caution.