Theo

Theo is the restless stepson of a wealthy, controlling father figure in Joe's new London social circle, more interested in parties and impulsive attachments than in living up to expectations. He drinks too much, chases connection wherever he can find it, and drifts through his privileged world looking for someone to actually see him.

Dylan Arnold plays him as a kid perpetually bracing for disappointment, which makes his neediness feel earned rather than pathetic. The show gives him just enough tenderness underneath the recklessness that you keep hoping he'll catch a break, even as his choices keep pulling him toward people who can't give him one.