Part of the reason I married the Wife is she lacks some of the stereotypical female traits that I find annoying.
Some women need a man. The Wife does not. She is very independent. We met in our 30's and I know she married me, not because she had to, but because she wanted to. Even the ticking of the biological clock is not a factor in her case, as I was the one who wanted to have kids, while she was a bit ambivalent about it.
However, there are some stereotypical biological imperatives that even she cannot overcome.
The wife has her thing once a week. In addition, one of us often goes out to shop or run errands while the other stays home with the kids. We used to try taking them both, but having twins is a license for anyone to come up to you and say "Twins! How cute. My friend/sister/relative has twins." I estimate anything we do with the girls takes at least 10% longer from people coming up to talk to you.
Although the Wife may not have had a strong biological drive to have kids, some of those drives kicked in after. Most strongly was guilt.
Once a week, when she goes out for the evening, she comes back feeling guilty that she has "abandoned" them, despite the fact that I also go out one evening a week. We both have personal things to do, and I often tell her to take some extra time for herself when she is picking up groceries to get her hair done, whatever she wants. She always comes back feeling guilty for leaving the kids for so long, despite the fact that it was my idea and it was only 2 hours. Believe me, I do not feel any guilt when I am away for a few hours and browsing through Best Buy.
I am not proud of it, but sometimes I will use this to my advantage and overstate how things were while she was gone. “This one wouldn’t stop crying, the other one wouldn’t settle down, I have a headache” etc. This is usually good for at least a clean up of the kitchen.
I expect this will become a high payoff strategy when the Wife goes back to work and I have them all day.