A chopper whopper is where a man grabs the base of the shaft and makes a chopping motion up and down. Hence the "chopper". For it to be a true whopper, the member must be large.
Jared was on a date with Tracey, and as a last ditch effort, pulled down his pants and shook his huge dick up and down in a chopping motion. Tracey was impressed and asked what was that. Jared replied, "that's a chopper whopper."
When the person making your Whopper has dank smelling fingers and you take your first bite and you can clearly taste Kush, then you take a look at your whopper and see it sparkling like the crystals on some good old bud.
"Hey Triston, this Whopper clearly tastes like the bud we sold that guy last week."
"Yea Hunter, I agree. I can see the bun sparkling and everything...OH and those aren't sesame seeds!"
"Yup, this must be a Stoner made Whopper."