Dumbledor'd
To ruin the ending of a book or a movie for someone, by revealing information
Person#1: The butler did it!
Person#2: Hey? Why did you tell me that, now the book is ruined to me.
Person#1: Yo dawg, I just Dumbledor'd yo' ass!
Person#2: Hey? Why did you tell me that, now the book is ruined to me.
Person#1: Yo dawg, I just Dumbledor'd yo' ass!