'Twilight' Facts You Never Knew, Including Why Robert Pattinson Was Warned About Working With Kristen Stewart & the 'Harry Potter' Star Who Auditioned

We bet that even the biggest Twilight superfans don’t know everything that happened behind the scenes of the movies.

The movies, inspired by Stephenie Meyer‘s novels about glittering vampires and werewolves, catapulted Kristen Stewart, Robert Pattinson and Taylor Lautner to international fame.

They’re fan-favorites that we are still talking about years after the final movie premiered in theaters. However, there’s so much involved in them, that we’re still learning new details on a regular basis.

For instance, did you know that a very famous Harry Potter star was in the running for a role? A High School Musical actor also auditioned for a popular part. In fact, one popular actress was in the running to play three different parts and never got cast.

Several actresses had to wear wigs, a key role was almost recast after the first movie and Robert was warned that he would be arrested if he did one thing wrong when he was first cast. There are also some secret details about that steamy sex scene.

On Thursday (November 21), the first movie is celebrating its 16th birthday. In honor of the occasion, we rounded up 17 secrets from the set of the movie for you to check out, including one that we just recently learned!

Scroll through the slideshow to learn so much more about the hit franchise…