1. In casual conversation, constantly ask: "Now what was the name of that kid with the scar again?"

2. Anytime they bring up the books, close your ears and sing loudly - then tell them they're spoiling it for you (even if you have no intention of reading them).

3. Ask what "HP" stands for.

4. When they begin to theorize, bluntly say "I think Harry is in cahoots with Voldemort and it's all just a huge publicity stunt."

5. Tell them you think the movies are better than the books.

6. Suggest they read the books on SparkNotes, because it's a lot faster.

7. Destroy any and all of their delusions that magic really exists and that they'll someday find Hogwarts.

8. Point and laugh unnecessarily loudly when they tell you how many times they've read each book.

9. Any time they mention JK Rowling, mention that you think she should just retire immediately.

10. Steal their wizard robes.

11. Wash off their lightning bolt tattoo.

12. Steal the dust jacket to their books.

13. Ask to borrow one of the books and return it with scribbles and notes alluding to the death of Harry.

14. Pronounce all of the character's names wrong, no matter how easy they are or how many times you've been corrected.

15. Offer to edit their fanfic, then re-write it to be about a delusional person who is convinced a book about magic is real.

16. Go on and on about how unrealistic all of it is.

17. Offer to mail a letter to Hogwarts, and really mail it to a shrink.

18. Draw mustaches on their Harry Potter posters.

19. When they start ranting and raving about the books/movies, say "That's nice!" in the same tone used to talk to a child.

20. Use logic to disprove all of the plot lines in the books.

21. Plant a snake in their room and laugh at their frustration when they can't communicate with it.

22. Write hate mail to JK Rowling, providing your friend's name and address.

23. Misquote the books as often as possible.

24. Try to convince them that Voldemort is really the good guy and the book is told from Harry's point of view - which is the only reason he comes off looking good.

25. When they start to retell a part of one of the books, say "Oh, yeah, and remember when..." - then completely make something up.