The vaginal lips of an African-American woman. Purple, describing the color of their genital, and plapper, referring to the 'plap' noise that is made by their labias abruptly smacking together. ('plap' noise usually made during intercourse)
Shineequa's purple plapper was rather disgusting. It was slimy, and smelled like rotted salmon.
Ever had to use a toilet at a not so clean rest stop. You don't wanna sit down and with the added elevation above the water you dread the caca water splash from the poop plop. Just lay down ample sheets of toilet paper on the surface the water to break the fall. That's a plopper stopper.
"Hey bro, that toilet was nasty. I put down a plopper stopper for sure."
"If you're going to use that restroom, I'd put down a plopper stopper."