Prisoner of Azkaban - Harry inflates Aunt Marge, inflicts damage, meets Cornelius Fudge but doesnt get expelled
-uses memory charm to make Marge forget about becoming an inflatable woman
Order of The Phoenix - Harry uses Patronus Charm infront of cousin to save themselves from dementors, almost gets expelled
- dementors sent by ministry
-decides not to use memory charm this time
-sends magic letter infront of the exact same muggle + his parents to tell Harry that he's expelled