Does a husband's calling his wife "my mother" (ya ummi) or "mom" (ya mama) constitute "zihar" requiring expiation, even if it is meant in the common vernacular and not as zihar, or when said in anger?

If a man habitually says "O my mother" to his wife and does not intend prohibition by it, this is not considered ẓihār, even if he says it in a state of anger. Imam Malik was of the opinion that a man saying to his wife "O my mother," "O my aunt (maternal)," or "O my aunt (paternal)" carries no consequence, and it is considered foolish talk. The Messenger of Allah (peace be upon him) forbade a man who said to his wife, "O my sister." Such a form of address does not make the wife unlawful, but it is considered foolishness, and the husband is not required to offer expiation for ẓihār. Intercourse between them remains permissible.