I believe it was a movie, although it’s possible it was an episode of a TV show. It centered on a teen girl and in one part of the show, a boy accidentally sits on her, mistaking her for a chair. She reflects that this is not the first time this has happened to her. The movie likely revolved around the girl being unpopular and feeling invisible. I believe it’s fairly recent and definitely was in English. Help?
Is it princess diaries?
I think there’s an episode of Buffy the vampire slayer with an invisible girl…
The Princess Diaries 100%