Good question! It depends on the parenting style of the family. In a super-strict household that leans heavily into traditionalism, children will be conditioned to refer to their father as "Sir" almost as a robotic address of deference.

When the parents have a more relaxed and looser parenting style, you probably won't hear "Sir" out of their kids' mouths. "Dad," "Daddy," or "Pops" will suffice.

There's also a middle ground of households that aren't super-strict but value discipline and structure more frequently than other parents will. In those households, a kid may call their father "Sir" on occasion -- but only when they feel the situation warrants it, such as when they're receiving a lecture, being punished, or they are adhering to their father's command out of respect.