Yes, there are quite a few. You can find some on fanfiction websites like Archive of Our Own. Just search for 'Adventure Time Finn and Marceline love' and you'll get a bunch of stories, some exploring their relationship in different ways, like how they might have fallen in love during their adventures.
One of the best Adventure Time fanfictions I've come across is 'The Land of Ooo's Hidden Treasures'. It sends Finn and Jake on a quest to find long - lost treasures across the Land of Ooo. It has a great mix of action, humor, and the kind of strange and wonderful elements that make Adventure Time so special.
AO3 is a great place. It has a tagging system that allows you to easily find the type of Adventure Time fanfiction you're interested in, whether it's about a specific character or a particular plotline. Another option is Tumblr. There are many fans who post their Adventure Time fanfictions there, and you might discover some really unique and creative works.
My favorite pairing in Adventure Time Finn love triangle fanfiction is Finn with Flame Princess. Their relationship is full of passion and energy. The storylines where Finn has to prove his love to Flame Princess against all odds are really engaging. For example, when he has to face challenges in the Fire Kingdom to win her heart back after a misunderstanding.
The relationships in Adventure Time Finn love triangle fanfiction are also influenced by the other characters in the show. Jake, Finn's best friend, often provides advice and sometimes comical interference. His perspective on Finn's love life can be a guiding force or a source of confusion for Finn. Also, the Ice King's wacky antics can sometimes accidentally impact the love triangle. He might kidnap one of the characters involved, which then throws the whole relationship dynamic into chaos.
In many of these fanfictions, authors often play with the idea of redemption for The Lich. They might create scenarios where Finn or Jake try to reach out to the good that might still be buried deep within him. This can lead to some really thought - provoking stories that deviate from the typical 'The Lich is just pure evil' narrative we see in the show.
It's completely inappropriate. Fanfiction should be a creative exploration of the existing story, characters, and themes in a positive and respectful way. 'Adventure Time' is a beloved franchise with a lot of positive values. Erotic fanfiction undermines those values and is not something that should be associated with it.
The popularity lies in the fact that Finn and Marceline are both very interesting characters on their own. Finn is the adventurous hero and Marceline is the cool vampire. When you put them together in a love story, it's like mixing two very different but exciting elements. Also, the Adventure Time world is so rich and full of possibilities that writers can create all kinds of scenarios for their love to develop in.
Love lost and found is a common theme in fanfiction. It often involves characters going through a difficult time of separation (love lost) and then reuniting in some unexpected way (love found). Writers use this theme to explore deep emotions and create engaging storylines. For example, in a Harry Potter fanfiction, two characters who were friends but had a falling out (love lost) due to a misunderstanding might later come back together (love found) during a battle against Voldemort, realizing their true feelings for each other in the face of danger.
In Adventure Time, Finn's love story is quite complex. He has strong feelings for Princess Bubblegum. Finn's love for her is pure and often drives his actions. For example, he would go on many adventures to protect her kingdom. However, their relationship also has its challenges, like when Bubblegum's responsibilities as a princess sometimes come between them.