According to his IMDb bio, Justin is a middle child; he has an older brother named Damian and a younger brother named Christian. Damian is a teacher and theater director at Weston High School in Connecticut, as well as a local stage actor. Meanwhile, Christian is an actor/producer/writer/director — just like his big brother Justin.

Their parents are R. James Long, who is a professor of philosophy at Fairfield University, and Wendy Lesniak, a former Broadway actress.