Breast milk isn’t just for babies. Believe it or not, a surprising number of adult men are into it, too. I recently surveyed more than 4,000 American adults about their sexual fantasies and nearly one-third of the men in my sample reported having fantasized about breast milk at least once before.

These fantasies can take a lot of different forms. Some guys get off on the thought of drinking it. (They literally dream of suckling on a woman’s breasts.) By contrast, others find the idea of simply watching a woman lactate or being lactated upon to be arousing.

Like all sexual interests that are outside of the mainstream, most guys who find breast milk to be a turn-on tend to keep it to themselves; however, at least a few are trying to turn their fantasies into reality. For instance, women who have tried selling excess breast milk to other mothers over the internet have reported “men coming out of the woodwork” to purchase it for themselves—so many, in fact, that there are now numerous “adult breastfeeding” sites that cater exclusively to grown-up men.

Also, at least in Japan, “lactation bars” have started popping up, which are exactly what they sound like. Instead of ordering a shot of whisky or vodka, you can get a glass of freshly pumped breast milk. Reportedly, if you’re willing to pay a premium, you can even drink straight from the, uh, tap. The question you’re probably asking yourself right now is “Why?”, as in, Why are so many guys turned on by breast milk?

Freud would probably say that these men just have some unresolved “mommy issues.” In other words, maybe guys with breast milk fetishes are, on some level, seeking emotional comfort or closeness to their mothers. Research suggests that there’s at least a hint of truth to this idea.

Breast milk fetishes, also known as lactophilia, partially overlap with Adult Baby Syndrome, which is just what you think it is: adults who find it sexually gratifying to dress up and/or act like an infant or child. This encompasses a wide range of behaviors, but often includes the desire to be taken care of as a baby—and to be nursed.

Research on Adult Baby Syndrome has found that, particularly among men, this kind of behavior is linked to the relationship they had with their parents. Specifically, guys who had negative relationships with their mothers are more likely to report wanting to engage in sexual activities with a mommy figure.

This suggests that, when breast milk fetishes overlap with Adult Baby Syndrome, there just might be something to the Freudian explanation. However, interest in being an adult baby is pretty uncommon, so there’s definitely a lot more to the story.

Research suggests that breast milk fetishes often co-occur with pregnancy fetishes. Indeed, a 2011 study published in The Journal of Sexual Medicine found that most people who were into one were also into the other. In addition, this study found that those who observed their mothers pregnant and/or breastfeeding prior to age 5 were the most likely to become erotically aroused by these things later in life.

This isn’t particularly surprising in light of other research finding that the features we look for in our romantic partners are associated with the physical characteristics that our parents had when we were younger. For instance, research has found that the older our parents are at the time we’re born, the more attracted we are to older partners in adulthood. If the sounds of this make you a little uncomfortable, you’re not alone.

The roots of lactophilia doesn’t always come back to mom, though. There are definitely other potential explanations. For example, this desire can potentially stem from a broader interest in BDSM. Some guys find it arousing to literally “milk” a submissive female partner, whereas others find it arousing to be force-fed breast milk by a dominant woman. In other words, breast milk is sometimes nothing more than a vehicle for expressing BDSM desires.

Other explanations are possible, too, of course. For instance, perhaps adult breastfeeding is just a logical extension of the popular role that breast and nipple stimulation play in heterosexual behavior today. Guys often kiss and orally stimulate their partners’ breasts already, so the fact that many move on to suckling (or at least fantasize about it) probably shouldn’t be all that surprising.

Like all sexual interests, the psychological origins of breast milk fetishes are complex and different guys appear to be into it for different reasons—although we’re guessing this isn’t what Kelis was singing about in her infamous “Milkshake.”


Justin Lehmiller, PhD is a sex educator and researcher at Ball State University, a Faculty Affiliate of The Kinsey Institute, and author of the blog Sex and Psychology. Follow him on Twitter @JustinLehmiller.