Xenodochy. This word means hospitality. But in a scary story, it could be a warped version of it. There's a house in the woods that offers 'xenodochy' but it's really a trap. Travelers who enter seeking shelter are never seen again. The owners of the house have a dark and sinister purpose for luring people in.
Friendship is a very common theme. Many fanfics start with them being friends and then the relationship evolving from there. For example, they might support each other in achieving their dreams like in the fanfic 'Dreams and Bonds' where Jinyoung helps Gongchan with his music and vice versa.
First, pick some words like 'dark', 'creaky', 'shadow'. Then start with a setting, for example, 'In a dark, old house, the creaky floorboards echoed as a shadow moved in the corner.' Just keep adding elements based on the words you've chosen.
One popular Jinyoung x Gongchan fanfic is 'Our Unspoken Bond'. It beautifully portrays their relationship with a lot of heartwarming moments and great character development. The story is set in a high - school backdrop where they start as friends and gradually discover deeper feelings for each other.
One common theme is the development of their relationship. It could be about how they gradually fall in love, with cute interactions and moments of realization.
You can try searching on some popular fanfiction websites like Archive of Our Own (AO3). They usually have a wide range of fanfics including ones about Baek In Ho and Hong Seol. Just use their search function and type in the relevant names.
Well, you need to focus on the emotions. For the sexy part, it could be the way the characters look at each other, their physical attraction. In a spooky love story, introduce elements like ghosts or other supernatural beings. The lovers could be in a situation where they are fighting against the spooky forces together, which brings them closer. Their love should be a bit forbidden or dangerous, which adds to the allure. For example, if one is a demon hunter and the other is a half - demon, their love is both sexy in their mutual attraction and spooky because of their different natures.