A wife can refer to her husband as "Daddy" once in a while, if he is a Daddy to someone. If he has a child, he became a Daddy when the child was born. Especially if the child is present, or in the room, the child would call him Daddy, and the wife can do that. Just like if the husband and wife are grandparents, she might call him "Grandpa" once in a while, but this would not occur very often. It could be an affectionate "nick-name".

Daddy = a word for 'father', used especially by children, derived from the word 'dad'. A wife can call her husband 'daddy' when talking about him with their children but not in other cases. I am not familiar with Chinese but my translators gave this answer in traditional Chinese for 'daddy': 爸爸 or 爸 whether or not they makes any sense I do not know. For 'father' they gave: 父親

Sexually speaking, it's not completely unheard of for a woman to call her man "daddy". I won't go any further...

“孩儿他爸”呗，哈哈！ 《樱桃小丸子》的妈妈就会称呼小丸子的爷爷为“爷爷”。。。I did noticed that in some American movies, the mom called his husband "Daddy".

A daughter calls her father 'daddy'. A wife doesn't call her husband 'daddy' A mistress refers to her lover as her 'sugar daddy' sometimes