There is no information indicating the existence of such works in mainstream literature. It could be something very niche or made - up, and if it involves inappropriate content, it's not likely to be promoted or found easily.
I don't know of a real - world Carl Luce associated with sex stories in a legitimate sense. It could be a fictional character in some improper or underground narrative.
One great 'luce and rachel fanfiction' could be the one where they go on an adventure together. It might involve them exploring a mysterious forest and facing challenges that test their friendship. They could encounter magical creatures and have to work together to overcome obstacles.
I'm not sure who Carl Weintraub specifically is just from this statement. He could be an ordinary person with a love for storytelling, or perhaps he's a local figure in a certain community known for his storytelling abilities.
One interesting story could be about Cam and Luce going on an adventure together. They might face challenges that test their relationship and in the end, come out stronger. It could involve them exploring a magical land and helping the locals there.
Another popular one could be 'A Red Herring Without Mustard'. It builds on the world established in the first book. There are more complex mysteries and Flavia's relationships with the other characters in the village start to develop in more interesting ways.
Perhaps a fanfiction where luce and daniel are new parents and they are learning how to balance their relationship with taking care of their baby. They might have some cute and comical moments as they struggle to understand what the baby needs at first.