If a man is sexually and romantically interested in both men and women, you’d probably assume he’s bisexual. But you’d be wrong. According to Ritch C. Savins Williams, author of Mostly Straight: Sexual Fluidity Among Men, there is an orientation that resides between heterosexual and bisexual, an orientation he’s coined “mostly straight.” Per Williams, these men “embrace sexual ambiguity over neat and simple identity boxes.” In other words, these are men who are primarily attracted to women, but also feel “a slight but enduring sexual or romantic desire for men.”

Playing devil’s advocate, I approached Williams with skepticism, asking if “mostly straight” is just an extraneous rephrasing of bi-curious. “A few mostly straight men initially identified as bi-curious before identifying as mostly straight,” Williams tells Playboy. “But bi-curious appears more of a ‘temporary’ position between straight and something else—perhaps bisexual or gay.” He contests mostly straight men are more certain of their orientation than “bi-curious” indicates. And as for identifying as bisexual, Williams has found that it registers “too gay” to these men and doesn’t feel true to their desires.

Williams often references a 2013 interview Out magazine had with Hunger Games actor Josh Hutcherson, where the 25-year-old casually copped to identifying as mostly straight. “Maybe I could say right now I’m 100 percent straight,“ he began. "But who knows? In a fucking year, I could meet a guy and be like, ‘Whoa, I’m attracted to this person’ … I’ve met guys all the time that I’m like, ‘Damn, that’s a good-looking guy,’ you know? I’ve never been like, ‘Oh, I want to kiss that guy.’ I really love women. But I think defining yourself as 100 percent anything is kind of near-sighted and close-minded.”

"Mostly straight” may be newly articulated, but the orientation has history. In examining national data, Williams traces men have long-reported a slight degree of sexual attraction to men. The reason we’re hearing about it now is youth culture has taken the mic and manifested a progressive culture that recognizes nuances in sexuality. “One cannot underestimate the acceptance of sexual and gender diversity among youth culture,” Williams states.

He hopes by igniting the conversation now, we can encourage men to further embrace sexual fluidity. “The key is to normalize it as prevalent and acceptable. I’d even like to see it celebrated and represented in all types of media,” he says. “We need more Josh Hutchersons!”

While strides toward sexual equality are being had, we’re far from the finish line. Williams wrote in The Cut that when he speaks of his work, people often assume these men are joking, or are closeted. In response to the sharp remarks, Williams argues if a young woman were to make the same claims, people wouldn’t be surprised. In fact, there’s a chance they’d find it hot.

Men aren’t equally regarded in such matters. “We like male sexuality to be simplistic and straightforward, but this can only be achieved by ignoring complexity,” Williams writes. “In so doing, however, we discount insights uncovered 70 years ago, when Kinsey demonstrated that sexuality is a continuum for both sexes. And, perhaps more critically, we negate young men who proclaim that their sexual and romantic desires and attachments are on a spectrum, not forever fixed in time or permanently housed in gay or straight identity boxes.”

Just how far will mostly straight men go with another man? Williams tells Playboy they will often make out, masturbate together and exchange oral sex, but will rarely engage in anal intercourse. “That said, although most of these men have said that they so strongly love intercourse with women that intercourse with men wasn’t desirable, several said, ‘If the right guy came along, it might happen.’”

When given the option to identify as mostly straight, Williams’ research has found that approximately five to 10 percent of men do so. This, by the way, is higher than the percentage of men who self-identify as gay or bisexual combined. As for the “he’s just secretly gay” narrative these men are often bludgeoned by, research has found that a mostly straight identity remains moderately stable over time. Even if a mostly straight individual drifts, the movement is usually between a straight and a mostly straight identity—almost never toward a bisexual or gay identity, which negates the closeted misconception.

In his research, Williams has found that mostly straight men have as many female sex partners and romances as straight men, they just happen to be more interested in having sex with another guy. In his research, Williams analyzed men who watched masturbation porn of both men and women and found mostly straight individuals had arousal patterns to women, identical to those of straight men. In contrast to straight men, mostly straight men were slightly aroused by men masturbating as well, though less so than bisexual men.

Williams argues the social ramifications for owning homoeroticism, no matter how small, will continue to prompt men to minimize or completely disown their desires. But Williams is hopeful. With increased tolerance, as displayed by millennials, society will continue to open doors for men to embrace the grayer areas of their sexuality.