真心不过半斤
[zhēn xīn bù guò bàn jīn]
This nickname reflects a somewhat cynical or disillusioned view of sincerity and genuine emotion, implying that no matter how true the feelings are, they're ultimately 'not even half a catty'—meaning they don't weigh much in reality. It expresses an idea of insincerity or lack of weight behind one's actions or promises in interpersonal relationships.