Now this is a new fascinating topic. As much as I hate the gender-stereotypes implied in the phrase "being the man" I don't know another way to say it.

For my relationship preference it's a balanced and dynamic thing. I'd be equally uncomfortable always "being the man" as I would be if he always was/had to "be the man".

IMO this usage means the person who has the ultimate control/direction over the household. It's his ultimate responsibility to take care of trouble, make sure there's enough money, and be the voice of reason and stability.

In practicality I'd never want to live where this pressure was put on one individual. I'd prefer a partnership where we have our areas of strengths, solve problems together, and deal with crises or decisions depending on who is in the best position at the time to do so.