Was reading a discussion of the problems of genre: your character really needs to know whether accepting food means a bond of hospitality and so protection -- or whether it's a trap.
One wonders if it could be both. If the Fair Folk could trap you in their hills or on their islands until all you know has perished because of the hospitality. To keep you safe. Or because their world is so much more wondrous than the human one that letting you go is doing you injury.
Or, of course, they weasel out of it because the food is illusion and the bond springs from real food.