0. The 5-second answer: bathing with your partner is a perk, but arousal "shows" differently in men and women
Same-sex couples get a very concrete everyday perk, as long as the facility's rules let both of them use the same bath.
You can go to a Japanese super sento (a big public bathhouse) with the person you love and get in the same bath together.
At a gender-separated bath, a man and a woman who came as a couple get split up at the entrance with a "see you later." A same-sex couple can stay together all the way through the bath.
Honestly, that's a little enviable.
But this is where Japanese internet commenters boot up their favorite interrogation.
"Admit it, you were staring."
If your partner is standing there naked right next to you, can you really stay completely indifferent?
And it gets more complicated.
Between two women, even if one of them is feeling her heart race, the physical signs visible from the outside are quite limited. Between two men, an erection can be fairly easy to notice, depending on the situation.
But the most important point is this: a visible bodily reaction is not the same thing as a person's feelings, intentions, consent, or behavior.
So here is the conclusion of this article:
- Sexual orientation doesn't mean being attracted to everyone of the same sex
- It's possible to be aware of your partner
- Some men's bodily reactions are easy to see from the outside
- Women's genital responses are very hard to read from a normal distance
- Even so, a bodily reaction alone can't tell you what someone is thinking
After bringing science into it, the "you were staring" trial turned out to rest on weaker evidence than you'd expect.
1. First, the basics: "I like women" does not mean "everyone in the women's bath is a sexual target"
There's one misunderstanding I want to knock down first.
A lesbian is in the women's bath. A gay man is in the men's bath.
Jumping from there to
"So she must be looking at everybody's naked body sexually, right?"
skips a whole logical step.
The American Psychological Association (APA) describes sexual orientation as an enduring pattern of emotional, romantic, and sexual attraction to people of a particular sex.
The key word is "pattern." It is not an ability to fall for every single person who fits the category.
A straight man walking down the street isn't sizing up every woman as a potential partner. A straight woman doesn't get aroused by every man inside just because she's seen the sign for the men's bath.
Same goes for gay and lesbian people.
Family, friends, coworkers, strangers, people you can't stand, your partner.
Even within the same sex, they all sit in different boxes in your head.
"Women can be someone I'm attracted to" and "the women here are people I'm attracted to" are two separate statements.
Mix them up and you end up treating sexual orientation like an "automatic lock-on to everything" feature.
It's not a video-game targeting system.
2. A partner is a special case: don't put "strangers" and "the person you love" in the same box
On the other hand, going all the way to
"Even if I'm attracted to the same sex, I feel nothing about anyone in the women's or men's bath"
is overstating it too.
You may feel nothing about strangers, but when the person you love is right next to you, that's different.
This is less about sexual orientation and more about your relationship with that person.
Someone you normally want to hold hands with, hug, touch, and think of as cute is now naked a few dozen centimeters away.
It would be strange if you didn't notice, even for a second.
So a same-sex couple at the bathhouse has an interesting asymmetry.
Opposite-sex couple: "We came together, but the curtain at the entrance splits us up."
Same-sex couple: "We came together. We undressed together. We washed together. We soaked together. And we leave together too."
The whole outing stays in one continuous piece.
That said, a public bath is a shared space, and even couples don't do overtly sexual things there.
What holds up here is only the inner part: "I like this person, so I'm a bit aware of them."
The manners of a public space are a separate matter and still apply.
3. Between women, it's very hard to tell from the outside whether someone is aroused
When women are sexually aroused, blood flow to the genitals increases, the vagina becomes lubricated, and the clitoris and the area around the vulva become engorged, among other changes.
But these aren't signs that someone sitting next to you in the bath can spot at a glance.
Most of them are internal or very local changes to begin with.
On top of that, a sento comes with a set of terrible conditions for observation:
- there's steam
- being warm changes blood flow throughout the whole body
- skin turns red
- everyone's wet
- staring at someone is unnatural in itself
So even if your partner is thinking,
"Wow, she looks so cute today,"
what the person next to her sees is basically just
"someone taking a bath."
Research also reports that in women, the feeling of being aroused and the physical genital response tend to line up less closely than in men.
That's the interesting part.
It's not only hard to see from the outside. Even with measuring equipment, you can't simply say that a physical response means the person feels the same level of arousal.
For the women's "you were staring" trial, there are hardly any witnesses and hardly any physical evidence.
4. Between men, an erection makes it suddenly visible, but it can't deliver a "guilty" verdict
For men, things are different.
An erection is a change in firmness and size caused by increased blood flow to the penis and other factors, so when you're naked it's easier to notice visually than a woman's genital response.
So between partners, this can happen:
"Hey, you looked just now."
"No I didn't."
"Your body is literally testifying right now."
The worst kind of automatic subtitles.
Taken alone, that puts men at a clear disadvantage.
But physiology is even less considerate of the mood.
Erections don't happen only because of sexual thoughts.
Some are reflexive responses to touch, some come from psychological stimulation, and some happen spontaneously during sleep. Sleep-related erections that come with REM sleep are studied as a natural physiological phenomenon in healthy men.
So,
an erection → he's aroused by the person in front of him right now
doesn't hold up logically.
The reverse is also true:
no erection → not aroused
isn't necessarily the case either.
Nervousness, temperature, physical condition, medication, fatigue, aging, anxiety: there are plenty of factors that affect the response.
In the men's bath, the body gives away spoilers a little more easily.
But spoiler subtitles are not the person's actual script.
5. What the research says: the meaning of r=.66 for men and r=.26 for women
There's a well-known study that speaks pretty directly to this.
A 2010 meta-analysis by Chivers and colleagues pulled together 132 studies published between 1969 and 2007 and looked at how closely self-reported sexual arousal matched genital responses.
In the analysis using independent samples, the results were:
- Men: r = .66
- Women: r = .26
Men showed a higher correlation between subjective arousal and genital response.
It's tempting to say,
"See, with men it all shows in the body."
But if you turn research into meme ammunition too eagerly, things go wrong.
What this result means is that in the male samples used in these studies, self-reports and genital measurements matched more strongly on average.
It does not mean "if you're a man, you can read his mind by looking at his erection."
It also doesn't mean "women are hiding their feelings."
Also, the way genital responses are measured often differs between men and women, and the content of the stimuli and the timing of self-reports affected how well they matched.
On top of that, many of the studies are old, and the participants don't represent everyone in modern society.
So the right way to use it is:
Men do tend to show more of a link between body and subjective feeling. But that doesn't turn the body into a device for reading an individual's mind.
That's as far as it goes.
6. At a sento, separate "looking," "staring," and "sexual behavior"
In a shared space where everyone is naked, other people's bodies coming into your field of view is unavoidable.
With a partner, your eyes will naturally wander there now and then.
But
- something briefly enters your field of view
- you're a bit aware of it because it's your partner
- you stare repeatedly
- you look so much that the other person or those around you feel uncomfortable
- you start sexual behavior in a public space
are all different stages.
It's sloppy to erase those differences and leap to "one glance = sexual misconduct," and just as sloppy to leap to "since we're partners, anything goes."
Even the Tokyo bathhouse guide presents public baths as a shared bathing space where you're expected to follow the facility's rules and bathing etiquette.
In short:
The freedom to feel your heart race inside and how you behave in a public space are billed separately.
That's true whether you're straight or gay.
7. "A bodily reaction does not equal intent": this is the one part to keep separate from the jokes
This topic is funny, but there's one thing worth separating out seriously.
The body can react before a person's will does.
A woman's genital blood flow and lubrication, and a man's erection, are physiological phenomena involving the autonomic nervous system, blood vessels, and nerve reflexes.
So from a bodily reaction alone, you can't read things like
"This person wants it." "This person likes this other person." "This person wants to engage in sexual behavior."
Conversely, just because no reaction is visible doesn't mean there's no affection or arousal.
The human body is a display of emotion, sure.
But it is not an admin panel that shows every log without a password.
Keep this in mind and you can laugh about it as a joke without jumping to weird conclusions.
8. The final verdict: for same-sex couples, the bathhouse is quietly a pretty big perk
In the end, if a same-sex couple can use the same bath,
going to the bath with the person you love and staying together inside the bath too
is honestly a big plus.
Unless you book a private bath or family bath, an opposite-sex couple has a hard time getting that experience, but here it happens on the ordinary bathing route.
And of course, with a partner, you might be a little aware of them.
Between women, that heart-pounding is very hard to spot from the outside. Between men, the body sometimes starts giving unnecessary testimony.
But the final verdict is this:
"You were staring" alone is not enough evidence.
Sexual orientation is not a switch that turns on desire for everyone. A bodily reaction is not subtitles for the mind. At a public bath, you follow public bath manners.
With all of that in place, the first thought still stands:
Being able to walk into the big bath with the person you love sounds nice.
Sources
- American Psychological Association, “Understanding sexual orientation and homosexuality”: https://www.apa.org/topics/lgbtq/orientation
- Chivers ML, Seto MC, Lalumière ML, Laan E, Grimbos T. “Agreement of self-reported and genital measures of sexual arousal in men and women: a meta-analysis.” Archives of Sexual Behavior. 2010. PMID 20049519: https://pubmed.ncbi.nlm.nih.gov/20049519/
- Levin RJ. “The physiology of sexual arousal in the human female.” 2002. PMID 12238607: https://pubmed.ncbi.nlm.nih.gov/12238607/
- Bouchard KN et al. “Concurrent measurement of genital lubrication and blood flow during sexual arousal.” Biological Psychology. 2019. PMID 31075363: https://pubmed.ncbi.nlm.nih.gov/31075363/
- MacDonald SM, Burnett AL. “Physiology of Erection and Pathophysiology of Erectile Dysfunction.” Urologic Clinics of North America. 2021. PMID 34602172: https://pubmed.ncbi.nlm.nih.gov/34602172/
- Schmidt MH, Schmidt HS. “Sleep-related erections: neural mechanisms and clinical significance.” 2004. PMID 14984691: https://pubmed.ncbi.nlm.nih.gov/14984691/
- Tokyo Sento Association (Tokyo Bathhouse Union), “How to take a sento bath”: https://www.1010.or.jp/guide/howto/
