It's when two people are extremely de-hydrated, but in order to save water, and hence the planet, they engage in a sexual activity of 69, having both genitals in respective oral capacities. They then proceed to relieve themselves of bodily fluids so it becomes a cycle of flowing liquid which will moisten up them throats.
"I'm an environmentalist! I do Sustainable Sex!"
by D Anal Chu Ang September 30, 2017