Not thiccubus anon. Would it actually be possible for a demon to get fat from having excessive amount of sex? How would a demon weight gain & loss work?
That's an interesting question, I hadn't thought about that aspect! I guess it would make sense for demons to gain weight this way. If sexual pleasure is their "food", then theoretically an excess of pleasure would be converted into fat.
Of course for most creatures, burning all these calories boinking would do the opposite and cause weight loss. But demons are a magical species, and magic defies logic in strange ways. It makes sense in a whimsical way, imo.
I've always imagined that a demons' body shape is determined by their genetics. For example, if their non-demon parent is an ogre, then they might have a tall, hulkish body type. If their non-demon parent is a dworf, then they might have a short, squat body type. And so on...
But I imagine they inherit genetics from both their demon and non-demon parents. Like, if a demon father had a hulking body type (due to having an ogrish parent himself), and the mother was a skinny elf, their demon offspring would probably be tall and lean. If the father was a demon with a dworf parent, and the mother was a dworf, their offspring is guaranteed to be short and squat like both of their parents.
I'm going to say genetics play a big role in how much fat and muscle a demon has naturally, but they can also gain and lose weight depending on how well "fed" they are.
Any physical activity that isn't sex probably burns calories and builds muscle as normal.