We always have this conversation on MN, and it's always about ironing or lunchmaking for the WOHP. And that's because the 'duties' thing can be split into three categories.
Caring for the children
Caring for the house
Caring for the husband
The top one comes first. If you have twin two-year-olds, it's pretty close to being a full-time job. Whatever time is left goes to caring for the house. How we all balance those two is always up for discussion and debate, obviously - I know some posters are a lot happier to use television than others, so that the housework gets done, and of course some children are happy to play independently and others aren't - but really, they're non-contentious.
The third one is contentious. I can't see any reason at all for a parent at home to be doing personal tasks like ironing and lunchmaking for a working parent, unless the working parent is, in order to support a SAH, working absolutely insane hours that wouldn't exist if they were both working. Most couples choose to have a SAHP if they believe it's important for the children and/or if it works out financially better than paying for childcare. So why, once the arrangement is in place, does the WOHP, who's always done his own personal tasks before, feel like he's entitled to a PA? Is it a belief that the SAHP has an easy life? Because that's clearly bollocks. Or just a general sense that working for pay makes your time more valuable, and therefore delineated better?
I have one 2.5 year old, who doesn't nap anymore, and I spent a 10 hour day with her today. We ran some errands, and I got breakfast and lunch made and cleaned up after, dinner done and a load of laundry washed and hung up, and that was it. I didn't sit down except to play with her, I certainly didn't take a break or have any time for myself at all, the entire day was entertaining her, setting up games and clearing them up, providing and clearing food, and the little bits of housework I could fit in around that. There is no possible way I can do more housework without doing less mothering. It's absolutely a zero sum game. If my husband thinks his shirt is more important than his daughter, he can whistle for it, frankly.