what was byrondoin with matches in bathroom in chapter 5

Byron has a habit of playing with matches, and Wilona repeatedly threatens to do "what she always said she would" if he keeps it up. Her house caught fire once when she was a child and she does not want the same thing to happen again. Despite these warnings, Byron continues his bad behavior; Kenny peeks in on him in the bathroom, where Byron is pretending to make a movie in which he lights toilet paper parachutes on fire and drops them into the toilet.