On a pain scale of one to 10, Chelsea ranks the epidural-free birth of her child as a six. Her husband’s spankings? Those are an eight.

First, he uses his hands for “warm-up” slaps. Then comes a combination of tools based on the specific infraction. The wooden spoon is the least severe; for the worst rule-breaking—like texting while driving (“It could kill me,” Chelsea admits) or moving money between accounts without his permission—she’ll be hit with something else: a hairbrush, a paddle, or a leather strap.

But this isn’t domestic abuse, Chelsea says. This is for Jesus.

Chelsea and her husband Clint, who asked that I use only their first names, belong to a small subculture of religious couples who practice “Christian Domestic Discipline,” a lifestyle that calls for a wife to be completely submissive to her husband. Referred to as CDD by its followers, the practice often includes spanking and other types corporal punishments administered by husbands—and ostensibly ordained by God. While the private nature of the discipline makes it difficult to estimate the number of adherents, activity in several online forums suggests a figure in the low thousands. Devotees call CDD an alternative lifestyle and enthusiastically sing its praises; for critics, it’s nothing but domestic abuse by another name.

Clint was in the room while I talked to Chelsea. They do everything together, including running their blog, Learning DD, which chronicles their exploration of domestic discipline. When Chelsea gets flummoxed by a question, she asks Clint for guidance in a voice so high-pitched that it belies her 28 years: “Honey, how long does the spanking usually last?” (About 5 minutes, Clint says.)

He has left bruises, Chelsea says, but it’s rare, and she attributes them to anemia.

You don’t have to be a Christian to practice domestic discipline, although many of its practitioners say they believe that domestic discipline goes hand in hand with their faith. Specifics of the practice vary by couple, though CDDers all seem to follow a few basic principles. Foremost, that the Bible commands a husband to be the head of the household, and the wife must submit to him, in every way, or face painful chastisement.

When a wife breaks her husband’s rules—rolling her eyes, maybe, or just feeling “meh,” as one blogger put it—that can equal punishments which are often corporal but can also be “corner time”; writing lines (think “I will not disobey my master” 1,000 times); losing a privilege like internet access; or being “humbled” by some sort of nude humiliation. Some practice “maintenance spanking,” wherein good girls are slapped on a schedule to remind them who’s boss; some don’t. Some couples keep the lifestyle from their children; others, like CDD blogger Stormy, don’t. “Not only does he spank me with no questions asked for disrespect or attitude in front of them, but I am also required to make an apology to each of them,” she writes.

After discipline, many wives report being held and comforted. And on Internet message boards dedicated to the practice, couples emphatically advocate for the CDD way of life. As such, there’s a temptation to file away domestic discipline into to the “different strokes for different folks” category. But mental-health and abuse experts see a potential for danger.

Jim Alsdurf, a forensic psychologist who evaluates and treats sexual psychopaths and is the author of a book on abuse in Christian homes, says CDD isn’t about religion—it’s an outlet for emotionally disturbed men with intimacy deficits.

“No fool in his right mind would buy this as a legitimate way to have a relationship,” Alsdurf says. “A relationship that infantilizes a woman is one that clearly draws a more pathological group of people.”

For Alsdurf, though, CDD sounds less like an act of violence and more like of an act of distorted sexual arousal. “If people want to spank each other, go ahead,” he says. “The problem of course, is if it’s done in a controlling and a mildly abusive way.” Like with all outer variables of sexual expression, he says, “If they’re not done in a healthy way they can become about abuse and control.”

Others are less equivocal. “It’s sick,” says Wendy Dickson, who runs an emergency shelter for women and children fleeing abusive homes in Evanston, Illinois. Women who receive beatings in the name God, she says, are no different than the women she sees every day in her shelter. Domestic abuse, which one in four U.S. women (PDF) will experience at some point in their lifetime, often conjures scenes of thundering rage, broken bones, and black eyes. But the most dangerous kind, Dickson says, is the emotional kind, because it keeps people trapped. “The definition of domestic abuse is power and control over another individual,” she says.

And as for women who seem content? Dickson says many of the abused women whom she helps also make excuses for staying in an unacceptable relationship. “Everyone just wants to maintain and tell themselves this is what they want,” she says.

Perhaps for these reasons, CDDers are a private group. As they see it, they’re fighting (and losing) a culture war against liberalism and feminism. There are no brick-and-mortar churches where adherents gather to pray and paddle. Instead, the ties that bind the community are formed in largely anonymous online communities.

There are dozens of online meeting places. On Fetlife, the Christian Domestic Discipline group has more than 500 members. The private Yahoo group boasts some 4,000 members. The topics on these forums range from the banal (“Happy Flag Day, everybody!”) to the political, such as a thread on whether Fox News anchor Megyn Kelly got it wrong on bread-winning moms. And then there are posts that are just plain disturbing: “My wife cries and writhes and begs me to stop during spankings, should I?”

Some women post questions about how best to convince their husbands to begin disciplining them, or pen distressed posts when the punishments wane in number or intensity.

Dig deeper, though, and you’ll find women who seem to want out. They describe being scared and in physical and emotional pain. The responses range from suggestions to submit more fully and try harder to leaving the relationship.

“I wanted the spankings to stop and my husband told me it was either DD and marriage or divorce,” one user named “Michelle” wrote on a popular domestic discipline blog. “I chose divorce. I couldn’t handle the pain of spankings anymore, emotionally or physically.” Leah Kelley, a CDD blogger and author of “spanking romance stories,” split from the man she had described as her “knight in beat up armor,” in 2010, citing her husband’s “deep-seated mental issues,” as the reason for the marriage’s end.

What seems to be the most obvious explanation for CDD, one acknowledged by some domestic discipline advocates not tied to the Christian church, is that the practice is a means to justify the fulfillment of a sexual fetish. On a CDD blog, “Sue” writes, “Boy do I wish more of the women in DD would admit to this. It’s a sexual fetish. There’s nothing wrong with it, but they try to make it so much more than it is.”

But the moral constraints of the church make it difficult for couples to be honest about the sexual nature of their desire, says Paul Byerly, who with his wife runs The Marriage Bed, a site dedicated to sexuality and religion. Byerly, who calls CDD a “distortion of what God intended,” believes that “women, particularly in the Christian church tend to be sexually repressed.” Domestic discipline, he explains, could be “a way around that”—a chance to explore sexual desires while still nominally acting in the name of Jesus.

Still, CDDers themselves reject this pain-for-pleasure explanation. “The pure CDD people don’t go there,” says Vera, who is both in a domestic discipline relationship as well as into sex play. “A lot of folks think of Fifty Shades of Grey—but this is not that,” she says.

Vera (not her real name), argues that abuse is all about intent. “He never punishes me when he’s angry,” she says of her partner. “He doesn’t yell. The worst thing I can do is disappoint him and I do that when I act on one of my character defects.”

And do men have any of these defects? Who is there to correct them? “He’s not perfect,” Vera says, “but it’s not my role to point that out. He self corrects.”

And as for what a man gets out of it, besides a woman who obeys his every command, Vera says her partner is satisfied by her growth. “He enjoys seeing the person he owns, his property, become the thing God wants her to be. It might sound weird, but that works for me.”