Dear Mary: how can I stop my dad treating my mum like a slave?

Q. Dad takes an old-fashioned approach to marriage: I have never seen him clear his plate and he does not know what’s in the kitchen cupboards. He also enjoys the benefits of a modern wife: my mother has worked (much) harder than him in their business for a long time and takes a lot of responsibility off him, although his name is on everything. There is no question of their love for each other but today, in the middle of discussing an important and stressful matter, he cut her off with ‘I’ll have my lunch when you’re ready’. Anything he doesn’t want to discuss is curtailed with ‘Can I have a cup of tea, please?’ in a tone one might use to remind a junior of her place. How should she respond? Mum is no Germaine Greer but she wants this to stop.
— Name and address withheld

A. The cultural norms were different when your parents began their marriage.