Filming happened the week after Chester Bennington died, so Adam's last name became Chester as a tribute to him.
Zeff Lawless's vision for the scene where Chris reluctantly helps the drunken Adam inside was so detailed that it wasn't story-boarded in advance. The storyboards just contained a note saying "Zeff will do his thing".
Thomas Fitzgerald moved everyone on set to tears with Adam's climactic monologue to Aaron in the garden.
Chris is an Irish boy who has lost his accent from years of living in England. Bobby Calloway is English born to Irish parents and has lived in Ireland since he was eight. Thomas Fitzgerald by contrast is half-English.
The brothers are named with an A and C naming convention after the brothers in East of Eden (Aron and Cal), who are in turn named after Cain and Abel from the Bible. Cal and Aron are also twins, and Thomas Fitzgerald has a twin brother.