To have a 'Rocky Waterfall' is to simultaneously urinate while having a dump.
Example 1. "I was so desperate for a wee, that when I was shitting I pissed at the same time. It looked like a rocky waterfall."
Example 2. "I was desperate for some really kinky porn, so I looked up golden showers with scat. What I got can only be described as a rocky waterfall"
When one's balls are sweaty enough to create a trickle flowing down the gouch and dripping right before reaching the butthole.
Damn homes...it's so muggy out here my gouch waterfall could fill up a pint glass.
That gouch waterfall I dealt with all day made these boxers smell rank as fuck.
When a woman drinks a beer after eating a Japanese hibachi meal, then stands over her man bottomless and pisses all over him.
I need to wash up, because my girl just gave me a Kentucky waterfall and I smell like urine.
Pooping while orgasming at the same time.
Would you like a brown waterfall?
Eye waterfall is referring to 'crying so hard you have a waterfall coming down your eyeballs'.
I have depression, so every night, I cry, then when I cry harder, I realize that I am having an eye waterfall.
To aim one's penis just right so at the point of ejaculation the stream of sperm flies overhead, narrowly missing the face in a matrix like fashion. Resembling a waterfall.
"Last night I was masterbating and totally shot a cascading waterfall"
When you make a girl cum at the beach
Guy 1: Yeah, we were at the beach and I gave her a sandy waterfall