Milk Rainbow 

When a chap is 'knocking one out' in his leisure time, lying on his back, preferably with someone watching from a distance, and blows a big load- quite high- that lands either in or around the mouth area. Making the shape of a low arching 'milk rainbow', result.

Derived from the ancient red indian word "milainbow" meaning to spunk on ones own face, or the face of a Yak, either by accident or on purpose. Such men in these tribes were worshipped for their big loads, and creative catching with the mouth abilities like a Jack Russell -thus commonly called "Jack-Russelling" in the gay community.

Andy-"Oh man last night I got spunk in my face!"

Peters-" Did it go in your mouth dude?"

Andy- "A little bit, why?"

Peters- "Mate, Milk Rainbow"

Milk Rainbow by "TheMurph" November 12, 2009

Rainbow Milk Challenge

Its where a small group of people get liter sized milk jugs one each, put random food coloring in them, and drink it as fast as you can. Then you try to puke.

Me and my friends are gonna do the rainbow milk challenge! Yay for rainbow puke!

Rainbow Milk Challenge by playmike5 January 23, 2013

Rainbow Milk 

Sperm that comes from a homosexual mans penis after he has an orgasm

"dude, that guy just squirted his rainbow milk all over that other mans back."

Rainbow Milk by DannyH'd December 16, 2009