beef rainbow 

When a mans dick is resting on a woman's vagina and the vaginal lips overlay the penis' shaft.

Don't go through my photos because you'll see some major beef rainbow pics, man.

beef rainbow by TBanger69 January 18, 2017

Roast Beef Rainbow 

(n.) When a female, standing on the ground, urinates upwards in an arc onto an elevated bed or other high place. A specialized form of the Golden Shower, this feat is more difficult for women than peeing standing up, even into a urinal.

"Can she use a urinal? Man, yesterday I seen her hit the ceiling with a roast beef rainbow!"

Roast Beef Rainbow by Adit June 15, 2008