她忠贞不二他始终如一
[tā zhōng zhēn bù èr tā shĭ zhōng rú yī]
'She is ever faithful; he remains always the same' signifies fidelity and commitment between two individuals in a relationship. It suggests that despite external changes, the hearts and intentions have not strayed or altered towards each other, highlighting the virtue of loyalty and steadiness in human relationships.