It depends on the way you say it. If your smiling laughing and blushing while saying “omg I don’t like you stahhpp” ( or something like that) yeah, it will be seen as a joke or a lie. However, If you actually tell them you don’t like them and stop paying attention to them, they’ll believe it. A funny trick around this is to individually tell a couple class mates that’s you don’t like ‘person’ anymore, but make it sound like you’re telling them a secret. The non-important gossip will spread and the story will be over with. AHAHA I did that, extremely petty but pretty effective.

So readers who obviously don't get real life are wondering why the FL does get it because she understands that telling someone she doesn't like them anymore will either be seen as a joke or an outright lie. Bnaooooodfbas.