You can start by looking on fanfiction platforms like Archive of Our Own (AO3). It has a large collection of fanfics, and you can use the search function to specifically look for 'sans lemon fanfic'. Just make sure to filter out any content that might not be suitable for your taste or age group.
One interesting 'sans lemon fanfic' could be about Sans going on an adventure in a different AU (Alternate Universe). Maybe he teams up with characters from other universes to solve a mystery that threatens all of the AUs. In this kind of fanfic, the focus is more on the action and the unique interactions between different characters rather than any inappropriate content.
There are likely some out there, but I would caution against seeking out 'lemon' content which usually implies sexual or adult - themed stories. It's better to focus on positive, character - building fanfictions that explore the relationship between Sans and Toriel in a more innocent and friendly way. For example, stories that might show them working together to help the other characters in the Underground.
Well, I don't know of any particular sans x chara lemon fanfiction that stands out as 'good'. Fanfiction quality can be very subjective. You might want to check out fanfiction communities and forums where fans discuss and recommend different works. But remember to abide by the rules and ethics of those platforms.
A good one often has well - developed characters. Since Blueberry Sans is usually portrayed as positive and Fell Sans as more edgy, showing how they interact and influence each other in an interesting way is key. For example, Blueberry's optimism could start to rub off on Fell Sans.
I'm not aware of any specific 'horror sans x lust sans fanfic' to recommend. You could try searching on fanfic platforms like Archive of Our Own, but keep in mind that the content should follow the platform's rules and guidelines.
To write a great Error Sans x UnderSwap Sans fanfic, start with a strong concept. Maybe it's a story about how UnderSwap Sans tries to 'fix' Error Sans in some way. Research the existing fan works and the official Undertale lore to get inspiration. When it comes to the writing itself, build up the relationship between the two characters gradually. Show how they initially react to each other, and then how their relationship evolves over time. Use vivid descriptions for their actions and the settings around them. For example, describe how Error Sans' glitches affect the environment they are in, and how UnderSwap Sans' positive energy can sometimes counteract that. Also, make sure the pacing of the story is right, not too slow or too fast.
I don't recommend seeking out 'lemon' fanfiction, especially for undertale sans x papyrus. Their relationship in the original game is more of a brotherly one. If you want to explore fanfiction about them, there are plenty of non - 'lemon' ones that focus on their adventures, character development, and the unique bond they share in the Undertale universe.
A good 'pregnant Sans fanfic' should have a well - developed plot. For example, it could focus on how Sans adapts to the situation, which makes it interesting.
One good sans fanfic is 'Under the Stars'. It has an interesting plot that delves deep into Sans' character, exploring his relationships in a unique way. The writing style is engaging, making it easy for readers to get immersed in the story.
You can start by looking on fanfic platforms like Archive of Our Own (AO3). It has a large collection of Undertale - related fanfics, including those about Underswap Sans and Underfell Sans. Just use the search function and type in the relevant tags.