If you’ve spent enough time on TikTok, Reddit, or deep in the world of internet sex slang , chances are you’ve come across the term “rainbow kiss.” And if your immediate reaction was “Wait…what is happening here?” you’re definitely not alone. The rainbow kiss meaning isn’t exactly self-explanatory, and despite the colorful name, it refers to a very specific sex act involving oral sex , menstruation, semen, and kissing. More specifically, Carol Queen, PhD , staff sexologist at Good Vibes , explains that a rainbow kiss typically happens when two consenting partners perform oral sex on each other while one person is menstruating, then kiss afterward, exchanging fluids in the process. The act is generally considered a form of fluid play , a broader kink category involving things like blood, semen, spit, or sweat. While rainbow kisses are definitely more niche than, say, your average quickie or shower sex fantasy, sex educators say conversations about them can still be useful.…