On Kelly's first day as Xander's stunt double on Buffy the Vampire Slayer, he managed to injure his shoulder and had to be taken to the hospital. Producers fired him after that, but when his brother, Nicholas Brendon (Xander) found out, he called in a few favors to get Kelly reinstated. After that, Kelly did an excellent job and managed to keep all of his bones intact.
During the height of Buffy the Vampire Slayer's popularity, Kelly was having lunch at a burger joint when he was accosted by a group of young Catholic schoolgirls who mistook him for his famous twin brother, Nicholas Brendon, who starred as Xander on the cult hit. But when Kelly tried to explain that they had the wrong brother, the girls didn't believe him and started pelting him with french fries!
Sometimes being a twin has its advantages. When Nicholas Brendon fell ill during the filming of the Buffy the Vampire Slayer episode, Intervention, Kelly was able to step in and take over his brother's role for the duration of the shoot.
Kelly has participated in the California AIDS Ride/Life Cycle since 2002.
Kelly has a twin brother, actor Nicholas Brendon of Buffy the Vampire Slayer. Kelly worked as his twin's stunt double on the cult hit.