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).
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.
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 set used for "Starcrossed" is the same as the X-303/BC-304 set used in Stargate: SG-1 and Stargate Atlantis.