Illustrative image of feminine hygiene products. (iStock)

Illustrative: Feminine hygiene products. (iStock)

My 12-year-old son and I stood in the feminine hygiene aisle at the local supermarket while I debated over which product to purchase. A curious kid, he wanted to know what these lovely purple and blue-hued boxes held.

And so I explained to him the inner workings of the female body.

Paling slightly, he asked, “And this happens every month? For how long?”

I told him usually around 30-45 years.

A quick study, he looked at the prices on the parcels in front of us and made a rough calculation.

“OMG! If you use one box a month, it’s like NIS 400 a year. Times 30 years and it’s like NIS 12,000! That’s a lot!”

I’m grateful that I can handle Israel’s relatively heavy “Tampon Tax.” About five years ago, feminist online magazine Jezebel put the annual costs of “owning a vagina” — including toilet paper and pubic hair removal — at $2,663.02. That 2011 figure approaches the median monthly salary of an American woman in 2016, according to Catalyst.org.

Today, October 11, marks the United Nations’ launch of “EmPOWER Girls: Before, during and after crises,” a year-long effort to “spur global attention and action to the challenges and opportunities girls face before, during, and after crises.”

While pubic hair removal is obviously a western luxury, there are so many of us out there in the world who cannot afford even the daily crisis of basic hygiene. Lacking sanitary napkins or reusable alternatives, these women and girls are ostracized by their community for a week a month, missing cumulative months of school until they often eventually drop out.

What is worse is that even as puberty affects both boys and girls at relatively the same age, often girls are taught to be ashamed of their changing body, just as boys are being praised for their virility.

There are any number of small cultural slights that could so easily be avoided: When shopping for school t-shirts, why must my lovely 12-year-old daughter purchase a woman’s size medium, when her only slightly smaller twin brother wears boys size 12? And why is it mission impossible to find shorts that cover her knees in accordance with the Ministry of Education dress code, while it’s the norm for boys?

Clearly puberty is rocky for both sexes, but it is girls who are made to feel “fat” for being average-sized, or ashamed for reproductive viability.

Today’s girls already know all this; it’s time to educate our sons against these insidious biases.

So if you speak with your daughters about normative biological functions in hushed tones behind closed doors, please also educate your sons on the same issues. This knowledge is “need-to-know.”

I assure you, learning about simple biology will not lead to “mixed dancing.” It’s time to arm our brothers, husbands, and fathers with a new tree of knowledge — even as we read the well-rooted stigmas against women in the Book of Genesis again this weekend.

Let’s build a new generation of men unafraid of women and their bodies. Your daughters will thank you for it.