First of all, Papa Smurf didn't create Smurfette. Gargamel did. She was sent in as Gargamel's evil spy with the intention of destroying the Smurf village, but the overwhelming goodness of the Smurf way of life transformed her. And as for the whole gang-bang scenario....it just couldn't happen. Smurfs are asexual. They don't even have reproductive organs under those little white pants.
actually....the smruf makers allowed them to use the smurf conversation because they said Donnie was correct in his interpretation!! So they gave them the rights