The act of a male and a female having intercourse until the male is almost at climax, where the male then pours multiple bottles of different coloured food colouring dye into his urethra before continuing. At the point of climax, the male fills the female with his semem mixed with the food colouring dye, which gives off the appearance of a rainbow.
"Elyalesiana was feeling pretty down, so I gave her a rainbow stream. She seemed to be fine after that."

"Dude, I fucked up."
"How, dude?"
"I gave my chick a rainbow stream on an unsafe day. Now I might end up with a rainbow-coloured baby."
by SmokyMcBong February 5, 2016
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