Green Rainbow 

The woman sticks several or more food-coloring full water balloons up her anus. The man proceeds to fuck her in the ass, thus breaking the water balloons in the woman's anus. At the same time as the color burst from her anus begins, the woman defecates on the man's junk. They cease the fucking and proceed to eat the rainbowy shit, only to throw it back up. The left over green rainbow left on the floor and body is called thusly, a Green Rainbow.

Fuck man, last night I walked into my mate's room and there was a fucking Green Rainbow. Shit smelled terrible but was strangely picturesque.

Green Rainbow by Grumpy Sam December 9, 2008

Double Rainbow

When two girls squirt at the same time, causing a double arc of lady Jizz across the room.

'Dude, I was watching Lesbian cams last night and totally saw a Double Rainbow!'

Double Rainbow by Huge Crystals April 16, 2014

double rainbow

V. Sex position where the girl doesa brdige, and the guy does another bridge under her, and they fuck.

Dude, yesterday we double rainbowed in the back of my car.

double rainbow by Mr. Awesome 1869 April 25, 2011

double rainbow

a double date between two homosexual couples

I went to gay day in disney world. I've never seen so many double rainbows in my life!

double rainbow by bigpoppiboi July 6, 2011

Double Rainbow

A rare event in which two lovers simultaneously orgasm. This is as rare as a double rainbow, hence the name.

Omg babe, we just had a double rainbow!

Double Rainbow by Nastasia91 November 29, 2019

Sing A Rainbow 

To vomit.
To "Shout Soup".

"I had a great night last night, though I did have to stop on the way home to Sing A Rainbow"

Sing A Rainbow by Georgeos August 9, 2009

End of the rainbow 

During sex, one partner fills his or her mouth with lucky charms, places a funnel in the other partner's asshole, proceeds to pour milk into the funnel, and drinks the milk out of the asshole. This results in an asshole milk-lucky charm concoction that is magically delicious and sexually arousing.

Man: You want to do an end of the rainbow?
Woman: Nah, the funnel doesn't fit anymore, it's too loose.

End of the rainbow by 2Interstellar April 17, 2015