“There are just certain things boys should never see their mothers do,” says Megan Fox, a sexy-as-they-come actress who has starred in a series of Hollywood blockbusters. Usually cast in the sultry eye-candy role, Fox says she’s done taking roles that require her to do, as she says, “near pornographic” scenes.

What changed her mind? Becoming a mother and quite naturally wanting to protect her children from the embarrassment of seeing a parent perform a sex act on screen.

“I don’t think my boys could handle that,” she told the Sun, adding: “They can’t separate the experience from the reality from the art. It gets very confusing when it’s your own mother.”

It’s not just shame, as she notes — though there is that. Fox shows she’s put some deep thought into this, understands the essence of her craft and how it’s perceived by the audience, not just the actor.

That’s especially important since the audience she’s worried about here is her family — specifically, her young children (and the one on the way). “I’m just acting, it’s just a job” may be a tempting way to wave away such concerns and build a wall between an actor’s professional and personal lives. But the nature of (good) acting is that it blurs those lines. Fox gets that.

Her comments are also notable because when famous mothers like, say, Kim Kardashian or Beyoncé or Madonna are out and about with no clothes on, and they get the “cover up, you’re a mother for Pete’s sake” critique, feminist writers are quick to defend them by leveling the charge of “slut-shaming.”

Fox’s perspective, prudish by Hollywood standards, is refreshing out here in the real world. Particularly in today’s culture, where female entertainers increasingly go by the “less (clothing) is more” rule and casually post naked pictures of themselves claiming they feel “empowered” and “liberated” to cover for their gross immodesty and (pardon the pun) naked self-promotion.

And unlike Fox, more and more actresses are blurring the line between traditional movie roles and pornography.

Consider the new Starz series “The Girlfriend Experience,” which follows the life of a full-time law student and part-time prostitute.

Men sort of love this mythical scenario, right? The smart-as-a-whip, yet financially strapped young woman who is only whoring around for money because she wants to improve her station in life.

For the role, Riley Keough, who, as the granddaughter of Elvis Presley, hardly has to turn to grimy soft-core pornography in order to get her foot in Hollywood’s door, was filmed totally nude, engaged in multiple sex scenes, simulated masturbation and inserted a tampon on screen.

Remember to add it to your family’s TV night Netflix queue.

Of course, “The Girlfriend Experience” isn’t some late night, after-hours, cheaply produced, badly acted, on-demand soft-core porno. “The Girlfriend Experience” is a well-funded premium cable channel series produced and directed by Academy Award and Palme d’Or winning director and producer Stephen Soderbergh. You don’t get much more respectable than that.

And while Keough admits she was uncomfortable filming many of the scenes, she seems to think she’s performing some sort of public service by embarrassing herself, saying, “We wanted to show things that you don’t really see, like the girl getting her period or the girl masturbating.”

Apparently women are in the dark about these things. Thanks for educating us all, Ms. Keough and Mr. Soderbergh. Brave.

Keough may feel better to see this as somehow edgy and empowering, but it’s more likely evidence of a race to the bottom, in which young actresses have fewer choices and taking sexually explicit and exploitive roles is the best way to get ahead.

Actresses aren’t the only ones feeling limited in Hollywood. According to a complaint filed by the ACLU, female producers and directors are also feeling sidelined by Hollywood studios that rarely select them to direct major films. This has prompted two federal government agencies to launch investigations into discrimination against female directors in Hollywood.

Megan Fox seems to understand that she can’t change the culture alone and that her unwillingness to take on the racy roles may limit her opportunities and fame. As such, Fox says she’s considering a move away from Hollywood.

Yet, Fox has done more than she knows. She’s voiced a concern that no doubt others in Hollywood share. And she’s alerted the public to her discomfort. That’s important because the Hollywood studio system isn’t entirely to blame for the limited roles offered to female actors. Consumers are increasingly demanding sexually explicit material.

Until consumers start shutting these shows off and start turning on shows that are more family-friendly and modest, nothing will change.

Julie Gunlock is a senior fellow at the Independent Women’s Forum.