(Courtesy of Harper Perennial) (Courtesy of Harper Perennial)

Like Christmas, its merry cousin, Valentine’s Day can be a trial for some people. Along with all the usual red-lace propaganda, this year the holiday comes jazzed up with “Fifty Shades of Grey,” the ultimate reminder that other, better looking lovers are having a lot more fun than you.

That pressure to be part of a couple can have particularly damaging effects on teenage girls and young women.

Leora Tanenbaum has spent decades studying the confusing and sometimes poisonous demands of our increasingly eroticized culture. In 1999, she coined the term “slut-bashing” and published a ground-breaking book called “Slut! Growing Up Female with a Bad Reputation.”

This month, just in time for V-Day, she’s back with an updated study called “I Am Not a Slut: Slut-Shaming in the Age of the Internet” (Harper Perennial, $15.99). Based on in-depth interviews with 55 young women, her new book surveys a world in which “many girls and young women like to identify themselves as sluts.”

Speaking with me from her office at Planned Parenthood in New York, she says, “I absolutely recognize that, for many individual women, embracing that label — ‘slut’ or ‘ho’ — and sharing it with their buddies can be comforting and empowering.” In other words, using the term “slut” is a way to take a cruel accusation and turn it on its head. She says that women are implicitly stating, “This pejorative slur does not apply to me, and I reject the double standard that underpins this slur. I’m going to reframe this double standard to prove that I am unapologetically sexual.”

But while Tanenbaum says that she respects that ironic usage of “slut,” she also sees dangers with this rhetorical strategy in the Internet age. “Every single one of the women I talked to who embraced the identity of sluttiness in a good way, ended up regretting it, because by presenting herself as ‘a good slut,’ she thought that she could control the narrative, and yet every single time, it backfired, and she ended up being labeled ‘a bad slut.’”

The culprit, as Tanenbaum sees it, is social media with its insistence that everything be shared. “Today, young women’s bodies are tracked and tagged and liked,” she points out. “Female bodies have so much currency in social media. It’s ramped up and amplified like never before.”

All those photos and comments on Instagram and Facebook are a landmine for young women to negotiate.

Tanenbaum says, “By providing evidence of one’s ‘good sluttienss,’ that material can be reshaped online [by others] as evidence of one’s ‘bad sluttiness.’ So an act of feminist resistance can be used as an opportunity to publicly humiliate the woman.”

In the end, Tanenbaum concludes that the reclamation of the word “slut” simply has not worked in practice. And she suggests that this is just one of the traps that popular culture sets. Her sobering analysis is especially pertinent for Feb. 14.

“There is a unique and crystallized pressure on young women to be partnered,” she says, “and what makes it really difficult for young women is that, at the same time, they must not seem desperate about it — to be always actively seeking male attention and yet never to be regarded as somebody who is seeking that attention. It must always be effortless. That’s what I find so challenging about these unspoken rules of femininity. We internalize all these crazy rules.”

Distressing as her report on contemporary culture can be, the final chapters of her book offer creative ways to use social media to fight back. Tanenbaum also includes a practical list of “Dos and Don’ts for Parents,” a “Slut-Shaming Self-Defense Toolkit” and a list of organizations where girls and young women can turn to for help and encouragement.