It is the sensational sensation of a dude who ties a feather to his tongue and licks your dangling balls while you are strapped to the bottom of a table.
Homie: Hey bro wanna play around with our penises?
Homie 2: Yea of course man will you give me a furry balls plopped menacinglyon the table?
Homie: omg I'm so fuckin' gay for you right now.
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."
When two men share the same room and sleep on different beds, they eventually get to know each other and discover their homosexuality. After having gay sex, the taker is considered to have had his "Mattress Popped", and therefore sleep on the same bed afterwards.
Makes more since if one slept on an airbed beforehand, where the definition comes from.
Brent: Hey, do Matt and Shane still live together in two different beds?
Shawn: Nah, Matt gave Shane a Popped Mattress and now they share a bed.