- Ability over Appearance: Word of God is that Eric was the only character written specifically to be a certain race (as being black forms a major part of his characterization). Everyone else was cast race neutral.
- Cast the Runner-Up:
- Aimee-Lou Wood was auditioning for the role of Lily, but got cast as Aimee instead.
- Patricia Allison auditioned for Lily as well, and then Kate, before she was cast as Ola.
- The Danza: Aimee-Lou Wood as Aimee Gibbs.
- Dark Horse Casting: Emma Mackey had barely any experience when she was cast as Maeve. In fact, at the time of her audition, she didn't even have headshots.
- Dawson Casting: As to be expected from a TV show about teenagers having sex, the cast of high schoolers are composed of twenty-something actors.
- Disabled Character, Disabled Actor: Like his character Isaac, George Robinson also uses a wheelchair.
- Separated-at-Birth Casting: Though they have different colouring, Alistair Petrie (Mr. Groff) and Connor Swindells (Adam) have similar enough facial structures to believably play father and son.
Trivia / Sex Education