A "rainbow kiss" refers to a specific intimate act involving two individuals who engage in kissing after one person has performed oral sex on the other, effectively mixing bodily fluids and creating a colorful effect, often metaphorically associated with the blending of different types of love or acceptance. It is a term used primarily in LGBTQ+ contexts.
The term "rainbow kiss" combines "rainbow," which traditionally symbolizes diversity, acceptance, and love across different identities, and "kiss," indicating an affectionate or sexual gesture. The usage of "rainbow" also highlights the LGBTQ+ community’s symbolism of inclusivity.