Most got it during a long car ride. Your dad decided to fill the silence with a dreaded parenting milestone — “the talk.” And, chances are, he left the chains, handcuffs, collars, ball gags and whips out of the birds and the bees. But behind many bedroom doors, from college campuses to CEOs’ penthouses, “alternative” sex rocks the headboards.

Sadomasochism (or S&M) has been growing in public recognition since the advent of pop-cultural taboo-busters such as “Fifty Shades of Grey” and Rihanna’s 2011 radio hit “S&M.” S&M is defined as the giving or receiving of pleasure — often sexual — from acts involving the infliction or reception of pain or humiliation. But casting such a broad blanket for very personal preferences can cause problems and confusion, as controversy has grown alongside S&M’s popularity.

“There are many versions of S&M, from mild to wild,” Pittsburgh-based sex therapist John Beiter said. “But it’s important to distinguish between the lifestyle and playing.”

Beiter considers “living the lifestyle” the extreme end of the S&M spectrum, in which participants consciously take the submissive or domineering sexual roles out of the bedroom and into their everyday life. They display overt signs of ownership on their persons at all times — handcuffs around their necks or whips in their back pockets.

But you’re not likely to see a Pitt student walking her boyfriend with a chain and ball gag down Forbes Avenue. The other end of the spectrum — those that restrict S&M to bedroom play — is much more prevalent, but still warrants some uncertainty among scholars.

“One thing that makes S&M a difficult topic for students to grapple with is that it is taking issues of dominance and power and explicitly sexualizing them,” said political science professor Andrew Lotz, who teaches a course about women in political theory in which the treatment of women in society is a topic. “It makes power sexy.”

But for some, it’s not the act itself that’s enticing. Bridget Miller, who asked her name to be changed because of S&M’s stigma in many circles, said it’s the fantasy aspect of the experience that draws her to it. Miller began S&M in her freshman year when she and her boyfriend began experimenting on a whim.

“You can become a different person in the bedroom, and the closed-door secrecy makes it even sexier,” she said.

As Beiter phrased it, “S&M provides a playground for exploration.”

The idea of playing out a fantasy, a staged disconnect from reality, is very important in keeping S&M behaviors safe and healthy, Beiter said.

“You negotiate a scene, and you determine the limitations each person is willing to experience,” he said.

And contrary to popular thought, he added, the submissive person — he or she in the shackles or receiving the paddle spanks to the butt — has situational power because of the arbitrary safe word, a precaution many S&M participants establish for the protection of themselves and their partners. Once they shout “foliage” or “pineapple” during an S&M experience, everything stops.

Miller said that the very ability to establish ground rules and be on the same page as your partner speaks volumes about the strength of the relationship.

“We got to the point where we’d go to the sex shop together, and I think we tried pretty much everything in there,” she said of her four-year relationship while at Pitt, which she has since ended.

Lotz, however, said he thinks that the line of consent becomes too muddled for those who practice S&M.

“If you learn to be domineering in the bedroom, then that’s problematic in life,” he said.

He worries that people like Miller might carry her experiences with her to her next relationship, where her partner might not be OK with it.

But Beiter argues the escapist qualities of sex provide a meaningful outlet for people. He’s seen many male corporate executives that play into the submissive role in S&M relationships.

“In everyday life [they] have to be the guy in charge,” Beiter said of a common personality type of people who engage in S&M. “They have so much responsibility and pressure to be in charge that they look to their sexual life as a pleasurable escape from all that responsibility.”

Although they disagreed on the implications of S&M, both Beiter and Lotz stressed the necessity of open lines of communication and trust in any healthy, sexual arrangement. And college life, hallmarked by its one-night stands and frequently alcohol-accompanied sexual rendezvous, might not be the ideal venue for beginning to explore an activity that requires such open dialogue.

But if you take the right precautions and consider all the possible residual consequences, you might find yourself perusing the chains and whips aisle of a sex shop alongside your significant other.