So the son goes to the market with the duck, manages to sell it for 7 dollars and promptly goes to the whorehouse and spends the extra 2 dollars he had earned and gets home by the end of the day.
About a month later the farmer needs a few extra bucks so he decides to use the same plan with his sons. For some reason this time he can’t find his smart son so he goes to the dumb son and says again
“take this duck to the market and sell it for 5 dollars. Any extra you earn you can go spend at the whorehouse on the way home.”
The dumb son leaves carrying the duck but after getting a couple miles out he gets horny and forgets what he was sent to do so he turns the truck straight to the whorehouse.
Upon arrival the lady running the place asks him how he expects to pay and he says “well I got this duck.”
The lady thinks it over and decides there’s no harm in getting paid a duck for a couple minutes. So she takes him into the next room and they have wild amazing sex. After they finish she says to him
“Wow that was fantastic. Can we please do this again? I’ll even let you keep the duck.”
And he happily agrees.
Now tired he goes to drive back home. On the drive the duck gets spooked and flies out the window, directly into the path of a semi.
The semi driver immediately pulls over and so does the son. The driver says “Oh my god I’m so sorry I killed your duck, it all happened in a flash. Please take 15 dollars for your troubles.” And the son happily agrees and goes on his way.
Once he arrives home his father asks him how much money he got.
The son proudly empties his pocket and shows his father the 15 big ones.
The farmer is stunned and asks him exactly what happened that day.
The son says “Well, I got a fuck for a duck, a duck for a fuck, and 15 bucks for a fucked up duck!”