Relationships

Why is it understandable to lose your temper and hit your girlfriend/wife but not your mother?

In my past, my father would used to hit my mother during heated arguments. She would get verbal but he would retaliate physical, always hitting first. Many years later, it stopped but at some point tables turned too; meaning dad reduced to words and mom got physical a couple times; she viewed that as her revenge. Overall, their whole marriage was like a war zone.

Ironically, my father was shocked the one time I got into an altercation with my mother (I was in my 20's) and slapped her back (not hard), making her cry. He told me that even many of the worst criminals don't hit their mothers. He was a bully in his school years and has slapped a girlfriend once too but never hit his mother. Does that even make sense?

Shouldn't a girlfriend or wife be just as valuable as a loved one in the family.. good enough for you not to hit her? If you wouldn't hit your mother, why is it ok to hit an spouse or wife/husband during an argument? I still fail to understand my father's logic. My boyfriend never hit his mother nor any girl and I expect him to never hit me either when we get married.
Updates
+1 y
A partner should also be someone you love that you simply wouldn't ever hit them in anger. A wife/husband is a family member too and should be just as valuable as a mother.
Why is it understandable to lose your temper and hit your girlfriend/wife but not your mother?
Post Opinion