The internet has a knack for turning the most obscure slang into headline-making phenomena, and this week’s jaw-dropper is something called the “rainbow kiss” — a term that has left many users somewhere between horrified, confused, and strangely curious.
What sounds like an innocent or even whimsical phrase is, in reality, a sexual act that’s got TikTokers, Reddit threads, and even wellness influencers buzzing — and in some cases, recoiling. If you’ve already Googled it, chances are you’re part of the growing online club of people saying they are “scarred for life.”
But for those who haven’t taken that digital leap, here’s the lowdown — in the most PG-13 way possible.
What Is a Rainbow Kiss?
A rainbow kiss involves a consensual sexual act between partners — often performed in the 69 position — during which one partner is menstruating. After oral sex is performed by both, the act concludes with a kiss that mixes menstrual blood and semen, hence the term “rainbow.”
Yes, it’s just as provocative as it sounds. And no, it’s not a newly discovered phenomenon. Sex educators say this act has been floating around the kink community for years, but like many niche trends, it has recently resurfaced and gone viral — thanks largely to social media platforms like TikTok.
The Internet Reacts: “I Should Never Have Searched That…”
The reactions to the rainbow kiss trend online have been a mix of fascination and horror.
“I am shaking,” one TikToker confessed.
“Why did I Google that?!” another commented, echoing what appears to be the collective regret of the curious.
Memes, reaction videos, and Reddit threads have exploded in response to the trend, with some users sharing genuine curiosity and others vowing never to approach the subject again.
Still, not everyone is repulsed. A smaller but vocal group online is defending the act as simply another form of sexual expression — one that challenges societal shame around menstruation and bodily fluids.
Experts Weigh In: “It’s Not for the Faint of Heart”
Dr. Wendasha Jenkins Hall, a sex educator in Atlanta, calls the rainbow kiss a “next-level sexual act,” describing it as a bold evolution of the traditional 69 position.
“This isn’t your everyday bedroom move,” she told Cosmopolitan. “It’s not for the faint of heart, but it’s also not inherently wrong. It’s about what’s consensual and comfortable for the people involved.”
Meanwhile, Neil Cannon, PhD, a certified sex therapist based in Denver, points out that the act has provoked strong reactions in part due to entrenched stigma around menstruation.
“When it comes to sex, all roads lead to shame,” Cannon says. “And when it comes to menstruation, that shame is deeply rooted. If people viewed blood as just another bodily fluid, maybe it wouldn’t be so shocking.”
Is It Safe?
Here’s where things get serious. While rainbow kisses may be consensual and exploratory, they are not without health risks.
Both semen and menstrual blood can carry sexually transmitted infections (STIs) — including HIV, hepatitis B and C, and syphilis. The risks increase significantly if either partner has open cuts, bleeding gums, or sores in or around the mouth.
Dr. Heather Irobunda, MD, an OB-GYN, strongly advises couples to be fully STI-screened and in good health before even considering experimenting with something like a rainbow kiss.
“This is definitely one of those acts where safety, trust, and testing are non-negotiable,” she says. “Get tested every three to six months if you’re sexually active — no exceptions.”
More Than Just a Trend
While the rainbow kiss may seem like just another outrageous internet trend, it highlights a bigger cultural shift in how people talk about sex, bodies, and kink. What was once whispered behind closed doors is now discussed openly, dissected in reaction videos, and debated in comment sections.
In the age of social media, sex slang and taboos aren’t just going viral — they’re reshaping conversations about pleasure, stigma, and consent.
So whether you find the idea fascinating or flat-out disturbing, the rainbow kiss is a stark reminder of how the digital age is changing not just how we communicate — but what we’re willing to talk about.