Question
Is it permissible for a person to call his wife's parents 'my dad' and 'my mom', and vice versa for his wife?
Answer
I say, and with God's help: everything that pertains to manners is recommended, and what you have mentioned falls under etiquette. Such behavior is recommended between the spouses as it is a form of respect and reverence, contributing to an increase in love and affection between the parents of the husband and wife. And God knows best.