No, women are not the second sex because they choose to work less
Kay Hymowitz, author of Manning Up: How the Rise of Women Has Turned Men into Boys has an op-ed in the WSJ entitled "Why Women Make Less Than Men." The article is fine until the end, at which point Hymowitz says:
We don't know if there is a way to design workplaces so that women would work more or men would work less or both. What we do know is that no one, anywhere, has yet figured out how to do it. Which means that for the foreseeable future, at least when it comes to income, women will remain the second sex.
Sorry, but if you work less, you make less. That doesn't make you the second sex, it makes you the first with choices that many men don't have or don't want.