David Hewlett and Kate Hewlett play two siblings, as they are in real life. They also play a brother and a sister in the science fiction TV show Stargate: Atlantis (2004).
Mars the Dog was scheduled to be euthanized, before being adopted by Jane Loughman and David Hewlett from an animal shelter. The Rottweiler-Terrier mix then starred in their film.
The show watched is called "Starcrossed," which is also the title of an episode from Gene Roddenberry's Andromeda (2000), in which Stargate SG-1 (1997) actor Michael Shanks met his future wife Lexa Doig, who also guest stared on several episodes of Stargate: SG-1, as did actors David Hewlett, Christopher Judge, and Michael Lenic.
The set used for "Starcrossed" is the same as the X-303/BC-304 set used in Stargate: SG-1 and Stargate Atlantis.