Moviefone is reporting that David Thewlis claimed he played Lupin as gay in the Harry Potter and the Prisoner of Azkaban movie in accordance with direction from the film’s director, Alfonso Cuarón. Thewlis apparently told the story during a recent press event at an Apple store in NYC. From the Moviefone article:
Thewlis revealed that director Alfonso Cuarón gave him a bit of advice which was to play the character as a ‘gay junkie.’
The story was picked up by The Advocate, Perez Hilton, and an assorted handful of blogs. None of which seemed to notice that Harry Potter fan site The Leaky Cauldron broke this story four years ago.
The story first came out when J.K. Rowling revealed that Dumbledore was gay and it seems to be an anecdote that Thewlis likes to reveal here and there.
Thewlis also notes that he corrected his take on the character for the ensuing movies, adding that he hadn’t yet read the books while filming Azkaban and had no idea that his character would eventually pair up with Tonks. (Although marrying a shapeshifter doesn't exactly preclude homosexuality or bisexuality on the part of the character, Rowling also explicitly informed the actor later that she didn't create Lupin with a queer sexuality in mind.)
The “Lupin is gay/no he’s not” story seems to come up from time to time, much like burgeoning urban legend-type stories regarding blondes or redheads being “extinct” in a generation’s time. One wonders if we’ll be hearing of this controversy again later this summer?
Stubby the Rocket is the mascot of Tor.com and has never received confusing character direction from Alfonso Cuarón, though not for lack of trying.