Responses
good quality
What's the character's other qualities? Their butt fetish may not make them relatable, but how they feel about it will. Think about how they feel. Are they troubled by it? Do they have a hard time dating? Ask yourself questions like that. They'll build your character up. Whether it's a bad quality depends on how your character feels about it.
I'm writing a fan-fiction and I want to know if people would relate to a character with a butt fetish, or would that be a bad quality?