Billy is a mortal assistant at the South Bay Social Services who has a crush on Paige Matthews. He was once bullied and teased by a co-worker due to his bad acne, though Paige fixed that with a spell. He briefly dated another co-worker named Lila, though it ended.
On Halloween, Billy asked Paige what she thought of his vampire costume, at which she replied she had a bad experience with vampires. After she invited him to the party at P3, he asked if she would dance with him if he changed his costume. Paige mentioned she was seeing someone and asked about Lila. Billy replied that things did not work out. Billy later showed up at the party in a pirate costume.
Some time later, Billy handed Paige a bunch of files and asked about her boyfriend. Paige replied that they had broken up and Billy attempted to ask her out. However, Paige was distracted by the arrival of Darryl Morris and left. She later left him to watch over the twins for a while.