Fairies are capricious. If you know their courts (Seelie, Unseelie), and their classifications (trooping, solitary), then you should know how best to approach them.
I liked Terry Pratchetts poem about the Fair Folk:
Elves are wonderful. They provoke wonder.
Elves are marvellous. They cause marvels.
Elves are fantastic. They create fantasies.
Elves are glamorous. They project glamour.
Elves are enchanting. They weave enchantment.
Elves are terrific. They beget terror.
The thing about words is that meanings can twist just like a snake, and if you want to find snakes look for them behind words that have changed their meaning.
No one ever said elves are nice.
Elves are bad.